6-CARBOXY-NORMORPHINAN DERIVATIVES, SYNTHESIS AND USES
THEREOF
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to United States provisional patent
application serial number 60/835,687, filed August 4, 2006, the entirety of which is hereby
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Opioids have been widely used as narcotic medications that activate opioid
receptors located in the central nervous system to relieve pain in patient therapy. Opioids,
however, also react with receptors in the peripheral nervous system, resulting in side effects,
including constipation, nausea, vomiting, urinary retention and severe itching. Most notable
are the effects in the "gastrointestinal tract (GI) where opioids inhibit gastric emptying and
propulsive motor activity of the intestine, thereby decreasing the rate of intestinal transit,
which can produce constipation. The effectiveness of opioids for pain therapy is often
limited due to resultant side effects, which can be debilitating and often cause patients to
cease use of opioid analgesics.
[0003] Endogenous opioid compounds and receptors may also affect activity of the
gastrointestinal (GI) tract and may be involved in normal regulation of intestinal motility and
mucosal transport of fluids in both animals and man. (Koch, T. R, et al., Digestive Diseases
and Sciences 1991, 36, 712-728; Schuller, A.G.P., et al., Society of Neuroscience Abstracts
1998, 24, 524, Reisine, T., and Pasternak, G., Goodman & Gilman's The Pharmacological
Basis of Therapeutics Ninth Edition 1996, 521-555 and Bagnol, D., et al., Regul. Pept. 1993,
47, 259-273). Thus, an abnormal physiological level of endogenous compounds and/or
receptor activity may lead to bowel dysfunction.
[0004] Compounds that bind to opioid receptors (rau-, kappa- and delta- receptors) have
been found useful in the treatment of diseases modulated by opioid receptors, for example, as
discussed above, functional gastrointestinal disorders, including, but not limited to irritable
bowel syndrome, constipation, ileus, nausea, vomiting; and pruritic dermatoses, such as
allergic dermatitis and atopy in animals and humans. Compounds that bind to opioid
receptors have also been indicated in the treatment of additional conditions, including eating
disorders, opioid overdoses, depression, anxiety, schizophrenia, addiction and dependence.

disorders (e.g., smoking, alcohol, narcotic, behavioral addictions and dependencies), sexual
dysfunction, shock, stroke, spinal damage and head trauma, among others.
[0005] Opioid antagonists such as naloxone, naltrexone, and nalmefene, have been
studied as a means of antagonizing undesirable peripheral effects of opioids. However, these
agents act not only on peripheral opioid receptors, but also on central nervous system sites, so
that they sometimes reverse the beneficial analgesic effects of opioids, or cause symptoms
of opioid withdrawal. Preferable approaches for use in controlling opioid-induced side
effects in patients include use of peripheral opioid antagonist compounds that do not readily
cross the blood-brain barrier. For example, the peripheral μ opioid antagonist compound
methylnaltrexone and related compounds have been disclosed for use in curbing opioid-
induced side effects in patients (e.g., constipation, pruritus, nausea, and/or vomiting). See,
e.g., U.S. Pat. Nos. 5,972,954, 5,102,887, 4,861,781, and 4,719,215; and Yuan, C. -S. et al.
Drug and Alcohol Dependence 1998, 52, 161. The S-methylnaltrexone compound has been
isolated and found to be a peripheral u opioid agonist, while the R-methylnaltrexone
compound retains antagonist activity. See, e.g., U.S. Patent Application Serial Numbers
11/441,452, filed May 25, 2006, published WO2006/127898, and 11/441,395 filed May 25,
2006, published WO2006/127899. Methylnaltrexone is commercially available. For
example, methylnaltrexone is available in a powder form from Mallinckrodt Pharmaceuticals,
St Louis, Mo., provided as a white crystalline powder freely soluble in water.
[0006] Thus, identification of new therapeutic agents and methods for the treatment of
side effects and/or disorders mediated by opioid receptor actions are useful for providing
alternatives and/or improvements to currently available therapies.
SUMMARY OF THE INVENTION
[0007] The present invention provides newly identified N-methyl-C-normorphinan
derivatives of formula I:


or a pharmaceutically acceptable salt thereof. The present invention also provides
pharmaceutically acceptable compositions comprising a provided compound, methods for
preparation and uses thereof. Provided compounds are useful as antagonists or partial
antagonists of kappa-, delta- and mu- opioid receptors.
[0008] One of ordinary skill in the art will recognize that formula I is drawn as a
stereochemically generic structure intending to represent all possible stereoisomeric forms
and is not intended to be limited to a racemic mixture.
[0009] In general, provided compounds of formula I, or pharmaceutically acceptable
compositions thereof, are useful for preventing, treating or reducing severity of side effects
resulting from use of opioids, including inhibition of gastrointestinal dysfunction (e.g.,
constipation, bowel hypomotility, impaction, gastric hypomotility, GI sphincter constriction,
increased sphincter tone, inhibition of gastrointestinal motility, inhibition of intestinal
motility, inhibition of gastric emptying, delayed gastric emptying, incomplete evacuation,
nausea, emesis (vomiting), bloating, abdominal distension), cutaneous flushing, sweating,
dysphoria, pruritis, urinary retention, etc. Provided compounds and compositions are useful
for administration to patients receiving short term opioid treatment (e.g., patients recovering
from surgery (abdominal, orthopedic, surgery from trauma injuries etc.), patients recovering
from trauma injuries, and patients recovering from child birth). Provided compounds and
compositions are also useful for administration to subjects receiving chronic opioid
administration (e.g., terminally ill patients receiving opioid therapy (e.g., an AIDS patient, a
cancer patient, a cardiovascular patient); subjects receiving chronic opioid therapy for pain
management; subjects receiving opioid therapy for maintenance of opioid withdrawal).
[0010] Additional uses of provided compounds and compositions include prevention,
treatment or reduction of severity of symptoms associated with disorders or conditions
resulting from normal or aberrant activity of endogenous opioids. Such disorders or
conditions include, among others, ileus (e.g., post-partum ileus, paralytic ileus),
gastrointestinal dysfunction that develops following abdominal surgery (e.g., colectomy,
including but not limited to, right hemicolectomy, left hemicolectomy, transverse
hemicolectomy, colectomy takedown, and low anterior resection) or hernia repair) such as
post-operative ileus, and idiopathic constipation. Provided compounds and compositions are
also useful in treatment of conditions including, for example, cancers involving angiogenesis,
inflammatory disorders (e.g., irritable bowel disorder), immune suppression, cardiovascular
disorders(e.g., bradycardia, hypotension) chronic inflammation and/or chronic pain, sickle

cell anemia, vascular wounds, and retinopathy, decreased biliary secretion, decreased
pancreatic secretion, biliary spasm, and increased gastroesophageal reflux.
[0011] Compounds and compositions of the present invention may also be useful for
modulation of dopamine levels for the treatment of dopamine dysregulation diseases, such as
schizophrenia, attention deficit hyperactivity disorder (ADHD), attention deficit disorder
(ADD), Parkinson's disease, hyperprolactinemia, depression, and addiction disorders. Thus,
provided compounds and compositions may be used to treat mammals (e.g. humans) for
narcotic dependence or addiction, alcohol dependence or addiction and nicotine dependence
or addiction; to palliate the effects of narcotic or alcohol withdrawal, to enhance the
outcomes of other narcotic or alcohol cessation therapies and to treat substance abuse and
behavioral dependencies (e.g. gambling, etc.).
DESCRIPTION OF THE DRAWING
[0012] Figure 1 depicts the X-ray diffraction pattern for Compound la and Compound la
recrystalized from ethanol/water.
[0013] Figure 2 depicts the UV spectrum for Compound la.
[0014] Figure 3 depict results from the neurotransmitter assay for Compound la.
[0015] Figure 4 depicts dose response curves for Compound la compared with naloxone
and CTOP obtained from the opioid functional antagonist assay described in Example 5 part
F.
DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS
[0016] In certain embodiments, the present invention provides a compound of formula I:

or a pharmaceutically acceptable salt thereof.
[0017] In other embodiments, the invention provides a compound of formula I A:


wherein X is a suitable anion. One of ordinary skill in the art will appreciate that X can be
derived from a variety of organic and inorganic acids. In certain embodiments, X is a
suitable anion other than trifluoroacetate. Such anions include those derived from an
inorganic acid such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid or
perchloric acid. It is also contemplated that such anions include those derived from an
organic acid such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic
acid, malonic add, methanesulfonic acid, optionally substituted phenylsulfonic acids, sulfinic
acid, optionally substituted phenylsulfuuc acid, trifluoroacetic acid, triflic acid, optionally
substituted benzoic acids, and the like. One of ordinary skill in the art will recognize that
such salts are formed by other methods used in the art such as ion exchange.
[0018] Compounds of the present invention contain asymmetric carbon atoms and thus
give rise to stereoisomers, including enantiomers and diastereomers. Accordingly, it is
contemplated that the present invention relates to all of these stereoisomers, as well as to
mixtures of the stereoisomers. Throughout this application, the name of the product of this
invention, where the absolute configuration of an asymmetric center is not indicated, is
intended to embrace the individual stereoisomers as well as mixtures of stereoisomers. In
certain embodiments of the invention, compounds having an absolute (R) configuration are
preferred. In some embodiments, provided compounds are in the (R) configuration with
respect to the nitrogen.
[0019] Exemplary compounds include:



wherein each X" is a suitable anion. Alternatively or additionally, compounds I-a through I-
hare provided in their free base form.
[0020] While all stereochemical isomers are depicted for compounds of formula I, it will
be appreciated that mixtures of enantiomers of these formulae are accessible enriched in any
stereoisomer via the present invention. In certain embodiments, a compound of formula I is
provided that is enantiomerically enriched in compound la. As used herein, the terms
"enantiomerically enriched" and "enantioenriched" denote that one enantiomer makes up at
least 75% of the preparation. In certain embodiments, the terms denote that one enantiomer
makes up at least 80% of the preparation. In other embodiments, the terms denote that at
least 90% of the preparation is one of the enantiomers. In other embodiments, the terms

denote that at least 95% of the preparation is one of the enantiomers. In still other
embodiments, the terms denote that at least 97.5% of the preparation is one of the
enantiomers. In yet another embodiment, the terms denote that the preparation consists of a
single enantiomer to the limits of detection (also referred to as "enantiopure").
[0021] In certain embodiments, a compound of formula I is provided wherein said
compound is enantiomerically enriched in compound la. In other embodiments, a compound
of formula IA is provided wherein at least 75% of the preparation is compound la. In still
other embodiments, a compound of formula la is provided wherein at least 80%, 90%, 95%,
or 97.5% of the preparation is compound la.
[0022] Where a stereoisomer is preferred, it may, in some embodiments be provided
substantially free of other stereoisomers. Thus, an stereoisomer substantially free of other
stereoisomers refers to a compound which is isolated or separated via separation techniques
or prepared free of the corresponding stereoisomers. According to another embodiment, the
present invention provides compound la substantially free of other stereoisomers.
"Substantially free," as used herein, means that the compound is made up of a significantly
greater proportion of one stereoisomer. In certain embodiments the compound is made up of
at least about 90% by weight of a preferred stereoisomer. In other embodiments of the
invention, the compound is made up of at least about 99% by weight of a preferred
stereoisomer. Preferred stereoisomers may be isolated from mixtures thereof by any method
known to those skilled in the art, including chiral high pressure liquid chromatography
(HPLC) and the formation and crystallization of chiral salts or prepared by methods
described herein. See, for example, Jacques, et al., Enantiomers, Racemates and Resolutions
(Wiley Interscience, New York, 1981); Wilen, S.H., et al., Tetrahedron 33:2725 (1977); Eliel,
E.L. Stereochemistry of Carbon Compounds (McGraw-Hill, NY, 1962); Wilen, S.H. Tables
of Resolving Agents and Optical Resolutions p. 268 (E.L. Eliel, Ed., Univ. of Notre Dame
Press, Notre Dame, IN 1972).
[0023] Compound la can be prepared by any available method. In some embodiments,
compound la is generally prepared according to Scheme I set forth below. In more particular
embodiments, compound la can be prepared as described in Examples 2-5 herein.
[0024] As depicted in Scheme I below, compound A (rnethylnaltrexone) is reacted to add
a suitable protecting group ("PG") at the phenolic hydroxyl, yielding compound B.
Compound B then undergoes a dibromination reaction, yielding compound C. Compound C
is then treated with aqueous potassium bicarbonate, to afford the diketone product, compound
D.

[0025] Benzil-benzilic acid rearrangement of compound D in the presence of a strong
base, such as sodium hydroxide followed by treatment with a strong acid, such as
hydrochloric acid results in a contracted ring structure compound F. Finally, Mitsunobu
inversion of the carboxylic acid group of compound F and displacement of a leaving group
resulting from the Mitsunobu reaction provides compound la.

[0026] Suitable hydroxyl- protecting groups are well known in the art and include those
described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M.
Wuts, 3rd edition, John Wiley & Sons, 1999, the entirety of which is incorporated herein by
reference. Suitable hydroxyl protecting groups, taken with the -OH- moiety to which it is
attached, include, but are not limited to, aralkylethers, allyl ether, and the like. Examples of-

OPG groups of compounds B, C and D include t-butyl ether, methyloxymethyl ether, benzoic
acid ester, benzyl ether, tetrahydropyranyl ether, acetic acid ester, pivalic acid ester, t-
butyldimethylsilyl ether, and the like. In certain embodiments, the -OPG group is -
OC(O)CH3.
[0027] When X" is the anion of an acid, compounds of formula IA may be treated with an
alternate suitable acid for salt formation. Examples of solvents suitable for use in connection
with preparation of alternative salt formation include polar solvents such as alkyl alcohols,
such as C1to C4 alcohols (e.g. ethanol, methanol, 2-propanol), water, dioxane, or THF
(tetrahydrofuran) or combinations thereof. In certain embodiments, the suitable solvent is a
C1 to C4 alcohol such as methanol, ethanol, 2-propanol, water, or combination thereof. A
suitable bi-phasic mixture of solvents includes an aqueous solvent and a non-miscible organic
solvent also can be used. Such non-miscible organic solvents are well known to one of
ordinary skill in the art and include halogenated hydrocarbon solvents (e.g. methylene
chloride and chloroform), benzene and derivatives thereof (e.g. toluene), esters (e.g. ethyl
acetate and isopropyl acetate), and ethers (e.g. MTBE, THF and derivatives thereof) and the
like. In certain embodiments, formation of a new salt is performed in a bi-phasic mixture
comprising water and toluene. In other embodiments, the suitable acid is water soluble such
that the reaction is performed in a mixture of toluene and a suitable aqueous acid, such as
aqueous hydrochloric acid.
[0028] Pharmaceutically acceptable salt(s), are those salts of compounds of the invention
that are safe and effective for use in mammals and that possess the desired biological activity.
Pharmaceutically acceptable salts include salts of acidic or basic groups present in
compounds of the invention. Pharmaceutically acceptable acid salts include, but are not
limited to, chloride, bromide, iodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate,
isonicotinate, acetate, lactate, salicylate, citrate, tartrate, pantothenate, bitartrate, carbonate,
ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucaronate, saccharate,
formate, carboxylate, benzoate, glutamate, sulfonate, methanesulfonate, ethanesulfonate,
benzensulfonate, p-toluenesulfonate, selenate, and pamoate (i.e., l,r-methylene-bis-(2-
hydroxy-3-naphthoate)) salts. Certain compounds of the invention can form pharmaceutically
acceptable salts with various amino acids. Suitable base salts include, but are not limited to,
aluminum, calcium, lithium, magnesium, potassium, sodium, zinc, and diethanolamine salts.
For a review on pharmaceutically acceptable salts see BERGE ET AL., 66 J. PHARM. SCI.
I-19 (1977), incorporated herein by reference. In some embodiments, salts of use in

compositions of the invention are those that have been described for methylnaltrexone, e.g.,
methylnaltrexone bromide, etc. However, the invention is not limited to these specific salts.
[0029] It is readily apparent that a compound of formula I contains both a quaternized
nitrogen group and a carboxylate group. One of ordinary skill in the art will recognize that
the carboxylate group of a compound of formula I can associate or interact with the
quaternized nitrogen of a compound of formula I. Such association or interaction between
two groups of a compound of formula I via an intermolecular interaction or can form
between those groups of the same compound via an intramolecular interaction. The present
invention contemplates both such forms.
[0030] Pharmaceutically acceptable salts of compounds of formula I can be prepared by
any suitable method resulting in formation a salt. One of ordinary skill in the art will
appreciate that compounds of formula I as prepared by the methods of the present invention,
may be treated with a suitable acid to form a salt thereof.
[0031] For example, in some embodiments, a salt of a provided compound is formed by
combining a compound of formula I and an appropriate acid. For example, compounds of
formula I and hydrobromic acid can be combined in about equimolar amounts. In certain
embodiments, compound la is treated with HBr to form the bromide salt thereof. In other
embodiments, compound la is treated with HC1 to form the chloride salt thereof. Treatment
of a compound with acid is optionally carried out in a solvent in which at least one of
compound la and HBr has at least some solubility. For example, compound la and HBr acid
can be dissolved together in a solvent, and then solvent can be removed to yield desired salt.
[0032] Suitable solvents for forming the salts of the invention include organic solvents
such as, for example, alcohols, ethers, hydrocarbons, halogenated hydrocarbons, nitriles,
mixtures thereof, and the like. In some embodiments, the organic solvent is a volatile solvent
such as methanol, ethanol, isopropanol, diethyl ether, pentane, hexane, benzene,
dichloromethane, acetonitrile, mixtures thereof and the like. In some embodiments, the
organic solvent is an alcohol such as methanol, ethanol, n-propanol, ispropanol, mixtures
thereof and the like. In some embodiments, the organic solvent is ethanol.
[0033] A salt of a compound of formula IA can also be prepared by replacing the anion
of a different salt of a compound of formula IA with a desired anion salt. For example,
compound Ia HC1, or other compound la salt, can be treated with hydrobromic acid or a
bromide salt to form compound la bromide salt. This anion-replacement reaction can be
optionally carried out in a solvent, such as an organic solvent described herein.

[0034] In some embodiments, isolated compounds of formula I may be prepared as a
solid form. In some embodiments, isolated compounds of formula IA may be prepared as a
solid form. One of ordinary skill in the art will recognize that solid form includes various
such forms including powders, particles, and the like. It will be appreciated that such solid
forms can be included in, e.g., tablets, granules, etc.
[0035] In other embodiments, isolated compounds of formula I may be prepared in
solution. In some embodiments, isolated compounds of formula IA may be prepared in
solution.
[0036] According to one aspect, the present invention provides a method for preparing
compound la:
wherein X" is a suitable anion, or a pharmaceutically acceptable salt thereof. In certain
embodiments, the method comprises preparation of a pharmaceutically acceptable salt of
compound la. In some embodiments, the salt is selected from the group consisting of a
chloride, sulfate, bisulfate, hydroxyl, tartrate, nitrate, citrate, bitartrate, carbonate, phosphate,
malate, maleate, bromide, iodide, fluoride, fumarate sulfonate,methylsulfonate, formate,
carboxylate, sulfate, methylsulfate and succinate salt of compound la. In some embodiments,
the salt is a chloride salt of compound la. In some embodiments, the salt is a bromide salt of
Compound la.
[0037] Additionally provided are methods for determining the presence of a compound of
formula I in a composition. In certain embodiments, methods of detection of a compound of
formula I below or above a designated level are preferred. Detection of individual
compound(s) in a composition by HPLC analysis and determining the presence of compound
below or above a specified level are preferred. Preferred concentration levels which are not
exceeded for one or more compound(s) as described herein.
Compositions, Uses, and Kits
[0038] Pharmaceutical compositions of the invention can be manufactured by methods
well known in the art. such as conventional granulating, mixing, dissolving, encapsulating,

Iyophilizing, or emulsifying processes, among others. Compositions comprising a compound
of formula I may be produced in various forms, including granules, dispersions, extrusions,
precipitates, or particulates, powders, including freeze dried,. rotary dried or spray dried
powders, amorphous powders, tablets, capsules, syrup, suppositories, injections, emulsions,
elixirs, suspensions or solutions. Compositions comprising a compound of formula I may
optionally contain additional excipients including, but not limited to, stabilizers, pH
modifiers, surfactants, bioavailability modifiers, etc., and combinations thereof.
[0039] Pharmaceutical compositions may be prepared as liquid suspensions or solutions
using a liquid, such as, but not limited to, an aqueous solution, water, an oil, an alcohol, and
combinations of these. Pharmaceutically suitable surfactants, suspending agents, or
emulsifying agents, may be added for oral or parenteral administration. Suspensions may
include oils, such as but not limited to, peanut oil, sesame oil, cottonseed oil, corn oil and
olive oil. Suspension preparation may also contain esters of fatty acids such as ethyl oleate,
isopropyl myristate, fatty acid glycerides and acetylated fatty acid glycerides. Suspension
compositions may include alcohols, such as, but not limited to, ethanol, isopropyl alcohol,
hexadecyl alcohol, glycerol and propylene glycol. Ethers, such as but not limited to,
poly(ethyleneglycol) , petroleum hydrocarbons such as mineral oil and petrolatum; and water
may also be used in suspension compositions.
[0040] Pharmaceutically acceptable carriers that may be used in these compositions
include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum
proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic
acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water,
salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium
hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate,
polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium
carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block
polymers, polyethylene glycol and wool fat.
[0041] According to a preferred embodiment, compositions of the invention can be
formulated for pharmaceutical administration to a subject. A "subject" as used herein means
a mammal to whom a composition or formulation is administered, and includes human and
animal subjects, such as domestic animals (e.g., horses, dogs, cats, etc.). Such
pharmaceutical compositions of the present invention may be administered orally,
parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an
implanted reservoir. The term "parenteral" as used herein includes subcutaneous, intravenous,

intramuscular, intra-articular, intra-synovial, intrastemal, intrathecal, intrahepatic,
intralesional and intracranial injection or infusion techniques. Preferably, compositions are
administered orally, intravenously, intramuscularly, or subcutaneously. Pharmaceutical
compositions of the invention may be designed to be short-acting, fast-releasing, or long-
acting. Still further, compounds can be administered in a local rather than systemic means,
such as local site administration (e.g., by injection).
[0042] Sterile injectable forms of the compositions of the invention may be aqueous or
oleaginous suspension Suspensions may be formulated according to techniques known in
the art using suitable dispersing or wetting agents and suspending agents. A sterile injectable
preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally
acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among acceptable
vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium
chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or
suspending medium. For this purpose, any bland fixed oil may be employed including
synthetic mono- or di-glycerides. Fatty acids, such as oleic acid and its glyceride derivatives
are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils,
such as olive oil or castor oil, especially in their polyoxyethylated versions. Oil solutions or
suspensions may also contain a long-chain alcohol diluent or dispersant, such as
carboxymethyl cellulose or similar dispersing agents which are commonly used in
pharmaceutical compositions, including emulsions and suspensions. Other commonly used
surfactants, such as Tweens, Spans and other emulsifying agents or bioavailability enhancers
which are commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or
other dose forms may also be used for the purposes of compositions. Compounds may be
formulated for parenteral administration by injection such as by bolus injection or continuous
infusion. A unit dose form for injection may be in ampoules or in multi- dose containers.
[0043] Pharmaceutical compositions of the invention may be orally administered in any
orally acceptable dose form including, but not limited to, capsules, tablets, aqueous
suspensions or solutions. In the case of tablets for oral use, carriers that are commonly used
include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also
typically added. For oral administration in a capsule form, useful diluents include lactose and
dried cornstarch. When aqueous suspensions are required for oral use, the active ingredient is
combined with emulsifying and suspending agents. If desired, certain sweetening, flavoring
or coloring agents may also be added.

[0044] Alternatively, the pharmaceutical compositions of the invention may be
administered in the form of suppositories for rectal administration. These may be prepared
by mixing the agent with a suitable non-irritating excipient which is solid at room
temperature but liquid at rectal temperature and therefore will melt in the rectum to release
the drug. Such materials include cocoa butter, beeswax and polyethylene glycols.
[0045] Pharmaceutical compositions of the invention may also be administered topically,
especially when the target of treatment includes areas or organs readily accessible by topical
application, including diseases of the eye, the skin, or the lower intestinal tract. Suitable
topical compositions are readily prepared for each of these areas or organs.
[0046] . Topical application for the lower intestinal tract may be effected in a rectal
suppository composition (see above) or in a suitable enema composition. Topically-
transdermal patches may also be used. For topical applications, the pharmaceutical
compositions may be formulated in a suitable ointment containing the active component
suspended or dissolved in one or more carriers. Carriers for topical administration of the
compounds of the invention include, but are not limited to, mineral oil, liquid petrolatum,
white petrolatum, propylene glycol, polyoxyethylene, polyoxypropylene compound,
emulsifying wax and water. Alternatively, the pharmaceutical compositions may be
formulated in a suitable lotion or cream containing the active components suspended or
dissolved in one or more pharmaceutically acceptable carriers. Suitable carriers include, but
are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax,
cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water.
[0047] For ophthalmic use, the pharmaceutical compositions may be formulated as
micronized suspensions in isotonic, pH adjusted sterile saline, or, preferably, as solutions in
isotonic, pH adjusted sterile saline, either with our without a preservative such as
benzylalkonium chloride. Alternatively, for ophthalmic uses, the pharmaceutical
compositions may be formulated in an ointment such as petrolatum.
[0048] The pharmaceutical compositions of the invention may also be administered by
nasal aerosol or inhalation. Such compositions are prepared according to techniques well
known in the art of pharmaceutical formulation and may be prepared as solutions in saline,
employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance
bioavailability, fluorocarbons, and/or other conventional solubilizing or dispersing agents.
[0049] The pharmaceutical compositions of the invention preferably are formulated for
administration to a subject having, or at risk of developing or experiencing a recurrence of,
effects or side effects of opioid receptor activity. The term "subject", as used herein, means

an -animal, preferably a mammal, more preferably a human. Preferred pharmaceutical
compositions of the invention are those formulated for oral, intravenous, or subcutaneous
administration. However, any of the above dose forms containing a therapeutically effective
amount of a compound of Formula I or an additional therapeutic agent of the invention are
well within the bounds of routine experimentation and therefore, well within the scope of the
instant invention.
[0050] In some embodiments, the pharmaceutical composition of the invention further
comprise another pharmaceutically active agent. In some embodiments, such other
pharmaceutically active agent is one that is normally administered to a subject with a disease,
disorder or condition being treated. In other embodiments, such other pharmaceutically
active agent is one that is administered to a subject to treat another disease, disorder or
condition.
[0051] An "effective amount" or "therapeutically effective amount" of a provided
compound, or pharmaceutically acceptable composition thereof, is an amount sufficient to
achieve a desired therapeutic and/or prophylactic effect. For example, an "effective amount"
is at least a minimal amount of a provided compound, or a pharmaceutically acceptable
composition thereof, that is sufficient for preventing, ameliorating, reducing, delaying, or
diminishing severity of one or more symptoms of a disorder associated with modulation of u-
, K-, or δ - opioid receptors, and/or for preventing, ameliorating, delaying or diminishing
severity of side effects associated with opioid analgesic therapy (e.g., gastrointestinal
dysfunction, etc.). Alternatively or additionally, an "effective amount" of a provided
compound, or pharmaceutically acceptable composition thereof, is an amount sufficient for
prevention, amelioration, reduction, delay or a decrease in the symptoms associated with a
disease associated with aberrant endogenous peripheral opioid or μ opioid receptor activity
(e.g., idiopathic constipation, ileus, etc.). The amount of compound needed will depend on
the effectiveness of the inhibitor for the given cell type and the length of time required to
treat the disorder. It should also be understood that a specific dosage and treatment regimen
for any particular subject will depend upon a variety of factors, including the activity of the
specific compound employed, the age, body weight, general health, sex, and diet of the
subject, time of administration, rate of excretion, drug combinations, the judgment of the
treating physician, and the severity of the particular disease being treated. The amount of
additional therapeutic agent present in a composition of the invention typically will be no
more than the amount that would normally be administered in a composition comprising that
therapeutic agent as the only active agent. Preferably, the amount of additional therapeutic

agent will range from about 50% to about 100% of the amount normally present in a
composition comprising that agent as the only therapeutically active agent.
[0052] In another aspect, the invention provides a method for treating a subject having, or
at risk of developing or experiencing a recurrence of, an opioid receptor mediated disorder.
As used herein, the term "opioid receptor-mediated disorder" includes any disorder, disease
or condition which is caused or characterized by an increase in opioid receptor (e.g., μ-, K-, δ
- opioid receptor) expression or activity, or which requires opioid receptor (e.g., μ-, K-, δ -
opioid receptor) activity. The term "opioid receptor-mediated disorder" also includes any
disorder, disease or condition in which inhibition or antagonism of opioid receptor activity
(e.g., μ-, K-, δ - opioid receptor) is beneficial.
[0053] As discussed above, the present invention provides compounds of formula I and
compositions useful in antagonizing undesirable side effects of opioid analgesic therapy (e.g.,
gastrointestinal effects (e.g., delayed gastric emptying, altered GI tract motility), etc.).
Furthermore, provided compounds and compositions may be used to treat subjects having
disease states that are ameliorated by binding μ-, K-, and/or δ -opioid receptors, or in any
treatment wherein temporary suppression of the μ-, K-, and/or δ -opioid receptor system is
desired (e.g., ileus, etc.). In certain embodiments, methods of use of provided compounds
and compositions are in human subjects.
[0054] Accordingly, administration of provided compounds and compositions may be
advantageous for treatment, prevention, amelioration, delay or reduction of side effects of
opioid administration, such as, for example, gastrointestinal dysfunction (e.g., inhibition of
intestinal mobility, constipation, GI sphincter constriction, nausea, emesis (vomiting), biliary
spasm, opioid bowel dysfunction, colic), dysphoria, pruritis, urinary retention, depression of
respiration, papillary constriction, cardiovascular effects, chest wall rigidity and cough
suppression, depression of stress response, and immune suppression associated with use of
narcotic analgesia, etc, or combinations thereof. Use of provided compositions may thus be
beneficial from a quality of life standpoint for subjects receiving administration of opioids, as
well as to reduce complications arising from chronic constipation, such as hemorrhoids,
appetite suppression, mucosal breakdown, sepsis, colon cancer risk, and myocardial
infarction.
[0055] In some embodiments, provided compounds and compositions are useful for
administration to a subject receiving short term opioid administration. In some embodiments,
provided compounds and compositions are useful for administration to subjects suffering
from post-operative gastrointestinal dysfunction.

[0056] In other embodiments, provided compounds and compositions are also useful for
administration to subjects receiving chronic opioid administration (e.g., terminally ill patients
receiving opioid therapy such as an AIDS patient, a cancer patient, a cardiovascular patient;
subjects receiving chronic opioid therapy for pain management; subjects receiving opioid
therapy for maintenance of opioid withdrawal). In some embodiments, the subject is a
subject using opioid for chronic pain management. In some embodiments, the subject is a
terminally ill patient. In other embodiments the subject is a person receiving opioid
withdrawal maintenance therapy.
[0057] Alternatively, additional uses for provided compounds and compositions
described herein may be to treat, reduce, inhibit, or prevent effects of opioid administration
including, e.g., aberrant migration or proliferation of endothelial cells (e.g., vascular
endothelial cells), increased angiogenesis, and increase in lethal factor production from
opportunistic infectious agents (e.g., Pseudomonas aeruginosa). Additional advantageous
uses of provided compounds and compositions include treatment of opioid-induced immune
suppression, inhibition of angiogenesis, inhibition of vascular proliferation, treatment of pain,
treatment of inflammatory conditions such as inflammatory bowel syndrome, treatment of
infectious diseases and diseases of the musculokeletal system such as osteoporosis, arthritis,
osteitis, periostitis, myopathies, and treatment of autoimmune diseases.
[0058] In certain embodiments, provided compounds and compositions may be used in
methods for preventing, inhibiting, reducing, delaying, diminishing or treating
gastrointestinal dysfunction, including, but not limited to, irritable bowel syndrome, opioid-
induced bowel dysfunction, colitis, post-operative, paralytic, or postpartum ileus, nausea
and/or vomiting, decreased gastric motility and emptying, inhibition of the stomach, and
small and/or large intestinal propulsion, increased amplitude of non-propulsive segmental
contractions, constriction of sphincter of Oddi, increased anal sphincter tone, impaired reflex
relaxation with rectal distention, diminished gastric, biliary, pancreatic or intestinal
secretions, increased absorption of water from bowel contents, gastro-esophageal reflux,
gastroparesis, cramping, bloating, abdominal or epigastric pain and discomfort, constipation,
idiopathic constipation, post-operative gastrointestinal dysfunction following abdominal
surgery (e.g., colectomy (e.g., right hemicolectomy, left hemicolectomy, transverse
hemicolectomy, colectomy takedown, low anterior resection) or hemia repair), and delayed
absorption of orally administered medications or nutritive substances.
[0059] Compounds of the present invention and compositions thereof are also useful in
treatment of conditions including cancers involving angiogenesis, immune suppression,

sickle cell anemia, vascular wounds, and retinopathy, treatment of inflammation associated
disorders (e.g.s irritable bowel syndrome), immune suppression, chronic inflammation.
[0060] Compounds of the present invention and compositions thereof described herein
can be used to modulate dopamine levels for the treatment of dopamine dysregulation
diseases. A "dopamine dysregulation disease or disorder" is meant a disease or disorder
characterized or mediated by abnormal levels of dopamine in the brain. Examples of
dopamine dysregulation diseases include schizophrenia, attention deficit hyperactivity
disorder (ADHD), attention deficit disorder (ADD), Parkinson's disease, hyperprolactinemia,
depression, Tourette's syndrome, and addiction. Methods of treating a dopamine
dysiegulation disorder by administering a compound of formula I or composition thereof are
provided.
[0061] As used herein, addiction refers to behavior resulting from compulsive substance
use- and is characterized by apparent total dependency on a substance or behavior.
Symptomatic of the addictive behavior is (i) overwhelming involvement with the use of a
substance or activity, (ii) the securing of supply of the substance or ability to engage in the
activity, and (iii) a high probability of relapse after withdrawal. Methods of treating
addiction by administering a compound of formula I or composition thereof are provided.
[0062] In still further embodiments, veterinary applications (e.g., treatment of domestic
animals, e.g. horse, dogs, cats, etc.) of use of compositions are provided. Thus, use of
provided compositions in veterinary applications analogous to those discussed above for
human subjects is contemplated. For example, inhibition of equine gastrointestinal motility,
such as colic and constipation, may be fatal to a horse. Resulting pain suffered by the horse
with colic can result in a death-inducing shock, while a long-term case of constipation may
also cause a horse's death. Treatment of equines with peripheral opioid antagonists has been
described, e.g., in U.S. Patent Publication No. 20050124657 published January 20,2005.
[0063] It will also be appreciated that provided compounds and compositions can be
employed in combination therapies, that is, a compound of formula I and compositions
thereof, can be administered concurrently with, prior to, or subsequent to, one or more other
desired therapeutics or medical procedures. Particular combination therapies (therapeutics or
procedures) to employ in a combination regimen will take into account compatibility of the
desired therapeutics and/or procedures and the desired therapeutic effect to be achieved. It
will also be appreciated that therapies employed may achieve a desired effect for the same
disorder (for example, a compositions may be administered concurrently with another
compound used to treat the same disorder), or they may achieve different effects (e.g., control

of any adverse effects). As used herein, additional therapeutic compounds which are normally
administered to treat or prevent a particular disease, or condition, are known as "appropriate
for the disease, or condition, being treated".
[0064] In some embodiments where a compound of formula I is present in
pharmaceutical compositions, the amount of the compound comprises from about 0.30 wt %
to about 99.0 wt%. In some embodiments where a compound of formula I is present in
pharmaceutical compositions, the amount of the compound comprises at least 5% of total
active compound contained in the composition. In some embodiments, the compound
comprises at least about 10% of total active compound, at least 20% of total active
compound, at least 50% of total active compound, at least 75% of total active compound, at
least 90% of total active compound, at least 95% of total active compound, at least 99% of
total active compound, or more in a composition.
[0065] In some embodiments, provided compositions include one or more other active
compounds in addition to compounds of the present invention. In some embodiments,
compositions comprise a provided compound and an additional opioid receptor antagonist
(e.g., a μ-, K-, δ -opioid receptor antagonist). In certain embodiments, compositions
comprise methyinaltrexone or a pharmaceutically active salt thereof.
[0066] In some embodiments, compositions comprise both an opioid and an opioid
receptor antagonist (e.g., .a μ-, K-, δ -opioid receptor antagonist). Such combination
products, containing both an opioid and an antagonist, would allow simultaneous relief of
pain and minimization of opioid-associated side effects (e.g., gastrointestinal effects (e.g.,
delayed gastric emptying, altered GI tract motility), etc.).
[0067] Opioids useful in treatment of analgesia are known in the art. For example, opioid
compounds include, but are not limited to, alfentanil, anileridine, asimadoline, bremazocine,
burprenorphine, butorphanol, codeine, dezocine, diacetylmorphine (heroin), dihydrocodeine,
diphenoxylate, ethylmorphine, fedotozine, fentanyl, funaltrexamine, hydrocodone,
hydromorphone, levallorphan, levomethadyl acetate, levorphanol, loperamide, meperidine
(pethidine), methadone, morphine, morphine-6-glucoronide, nalbuphine, nalorphine,
nicomorphine, opium, oxycodone, oxymorphone, papaveretum, pentazocine, propiram,
propoxyphene, remifentanyl, sufentanil, tilidine, trimebutine, and tramadol. In some
embodiments me opioid is at least one opioid selected from alfentanil, buprenorphine,
butorphanol, codeine, dezocine, dihydrocodeine, fentanyl, hydrocodone, hydromorphone,
levorphanol, meperidine (pethidine), methadone, morphine, nalbuphine, nicomorphine,
oxycodone, oxymorphone, papaveretum, pentazocine, propiram, propoxyphene, sufentanil

and/or tramadol. In certain embodiments, the opioid is selected from morphine, codeine,
oxycodone, hydrocodone, dihydrocodeine, propoxyphene, fentanyl, tramadol, and mixtures
thereof. In a particular embodiment, the opioid is loperamide. In another particular
embodiment, the opioid is hydromorphone. In other embodiments, the opioid is a mixed
agonist such as butorphanol. In some embodiments, the subjects are administered more than
one opioid, for example, morphine and heroin or methadone and heroin.
[0068] The amount of additional active compound(s) present in combination
compositions of the invention will typically be no more than the amount that would normally
be administered in a composition comprising that active compound as the only therapeutic
agent In certain embodiments, the amount of additional active compound will range from
about 50% to 100% of the amount normally present in a composition comprising that
compound as the only therapeutic agent.
[0069] In certain embodiments, provided compounds and compositions may also be used
in conjunction with and/or in combination with conventional therapies for dopamine
dysregulation disorders, cancers, immune suppression, inflammatory disorders, and/or
dependence or addiction disorders. For example, conventional therapies include, but may not
be limited to antidepressants, stimulants and/or other compounds useful in treatment of
affective disorders such as schizophrenia, depression, ADHD, ADD, Parkinson's disorder,
and addiction disorders. In still other embodiments, compositions may be used in
conjunction with behavioral therapy useful in treatment of such disorders.
[0070] In certain embodiments, provided compounds and compositions may also be used
in conjunction with and/or in combination with conventional therapies for gastrointestinal
dysfunction to aid in the amelioration of constipation and bowel dysfunction. For example,
conventional therapies include, but may not be limited to functional stimulation of the
intestinal tract, stool softening agents, laxatives (e.g., diphelymethane laxatives, cathartic
laxatives, osmotic laxatives, saline laxatives, etc), bulk forming agents and laxatives,
lubricants, intravenous hydration, and nasogastric decompression.
[0071] In other embodiments, compounds of the present invention and compositions
thereof are useful in preparation of medicaments, including, but not limited to medicaments
useful in the treatment of side effects of opioid administration (e.g., gastrointestinal side
effects (e.g., inhibition of intestinal motility,GI sphincter constriction, constipation nausea,
emesis (vomiting)), dysphoria, pruritis, etc.) or a combination thereof. Compounds and
compositions of the present invention are useful for preparations of medicaments, useful in
treatment of patients receiving short term opioid therapy (e.g., patients suffering from post-

operative gastrointestinal dysfunction receiving short term opioid administration) or subjects
using opioids chronically (e.g., terminally ill patients receiving opioid therapy such as an
ADDS patient, a cancer patient, a cardiovascular patient; subjects receiving chronic opioid
therapy for pain management; or subjects receiving opioid therapy for maintenance of opioid
withdrawal). Still further, preparation of medicaments useful in the treatment of pain,
treatment of inflammatory conditions such as inflammatory bowel syndrome, treatment of
infectious diseases, treatment of diseases of the musculokeletal system such as osteoporosis,
arthritis, osteitis, periostitis, myopathies, treatment of autoimmune diseases and immune
suppression, therapy of post-operative gastrointestinal dysfunction following abdominal
surgery (e.g., colectomy (e.g., right hemicolectomy, left hemicolectomy, transverse
hemicolectomy, colectomy takedown, low anterior resection), idiopathic constipation, and
ileus (e.g., post-operative ileus, paralytic ileus, post-partum ileus), and treatment of disorders
such as cancers involving angiogenesis, chronic inflammation and/or chronic pain, sickle cell
anemia, vascular wounds, and retinopathy.
[0072] Still further encompassed by the invention are pharmaceutical packs and/or kits.
Pharmaceutical packs and/or kits provided . may comprise a provided compounds and
compositions and a container (e.g., a vial, ampoule, bottle, syringe, and/or dispenser package,
or other suitable container). Optionally, instructions for use are additionally provided in such
kits of the invention. Such instructions may provide, generally, for example, instructions for
dosage and administration. In other embodiments, instructions may further provide
additional detail relating to specialized instructions for particular containers and/or systems
for administration. Still further, instructions may provide specialized instructions for use in
conjunction and/or in combination with additional therapy.
[0073] In order that the invention be more fully understood, the following preparative and
testing examples are set forth. These examples illustrate how to make or test specific
compounds, and are not to be construed as limiting the scope of the invention in any way.
EXEMPLIFICATION
Example 1
Identification and Characterization
[0074] Previously, at least three degradation products of roethylnaltrexone were
demonstrated from HPLC analysis in 20mg/mL isotonic saline solution (identified as RRT
peaks at about 0.72, 0.89, and 1.48 when products were analyzed by HPLC). See, e.g., U.S.

Patent Application Publication No. 20040266806, published December 30, 2004. We
examined 20mg/mL saline methylnaltrexone solutions for production of degradants, and
identification of degradants, as well as identification of inhibitors of formation of different
degradant products. We have identified and characterized degradants which accumulate in
certain methylnaltrexone solutions. In these degradation experiments, and in the
formulations prepared in the examples, (R)-N-methylnaltrexone was used having less than
0.15 weight percent (S)-N-methylnaltrexone.
[0075] For HPLC analysis a Prodigy ODS-3 15cm X 2.0mm, 3um particles
(Phenomenex) HPLC column at a flow rate of 0.25 mL/min, using the following eluent:

[0077] Naltrexone base, S-methylnaltrexone, and O-methyl methylnaltrexone (also
refered to as 3-methoxy naltrexone methobromide) are each compounds found in initial
production samples. Additional impurities/degradants formed and identified include 8-

ketomemylnaltrexone bromide (RRT 0.49), the aldol dimer (RRT 1.77), O-methyl
methylnaltrexone (RRT 1.66), and the 2,2 bis-methylnaltrexone (RRT 1.55), as well as
additional degradants resulting at relative retention time of 0.67, 0.79 and 2.26.
[0078] Each of the three additional degradants were identified by NMR analysis
following isolation from column eluates, and further characterized as described herein. We
found the 0.79 degradant is a novel isolated compound, identified as a ring contracted form of
(R)-N-methylnaItrexone: ((3R,4R,4aS,6aR, 11 bS)-6-carboxy-3-(cyclopropylmethyl)-4a,6,8-
trihydroxy-3-methyl-l ,2,3,4,4a,5,6,6a-octahydro-4,l 1-
me1bano[l]berizoruro[3',2,:2,3]cyclopenta[l,2-c]pyridin-3-ium). Thus, the present invention
provides a compound of formula la, wherein said compound is substantially free of
methylnaltrexone. Additional description of the NMR and MS data analysis which led to the
identification of compound la is further described in A and B below.

A. 1H and 13C NMR analysis:
[0079] The structure of compound la was elucidated by interpretation of ID and 2D
NMR data (1H, 13C NMR, COSY, HSQC, HMBC, TOCSY, ROESY). The 1H NMR
spectrum in D2O showed all proton signals of methylnaltrexone except for the 4
exchangeable hydroxyl and carboxylic protons (see Scheme A: Numbering System of
methylnaltrexone Compound la). This numbering system is utilized for analytical method
designation herein, and does not reflect IUPAC nomenclature designations.


Scheme A: Numbering System of (R)-N-methylnaltrexone and Compound la
[0080] By comparison, it was evident that the spectrum of compound la did not show the
signals at 8 2.31 and 2.8-3.2, which was assigned to the C-7 methylene protons (H-7b and H-
7a) of the parent compound (R)-N-methylnaltrexone. The loss of the C-7 methylene protons
was further supported by the appearance of a pair of sharp doublets at 5 2.49 and 1.64 with
coupling constant of 14.2 Hz, assigned to H-8a and H-8b at 5 2.49 and 1.64, respectively.
These two proton signals were strongly coupled to each other in the COSY spectrum but
exhibited no further spin-spin coupling to any other protons. This evidence indicated that H-
8a and H-8b were flanked by two quaternary carbons with no adjacent H-7a and H-7b
protons. In the HSQC spectrum, both H-8a and H-8b were correlated to a carbon resonance
at 5 50.4, typical chemical shift for C-8 type methylene carbon. Detailed analysis of the
HMBC spectrum revealed that both H-8a and H-8b showed two-bond correlations to C-6 at δ
80.6 and to C-14 at 8 77.3, typical oxygenated quaternary carbons, and three-bond
correlations to C-7 at 8 180.4, assigned to the carboxylic group C-7. Additional three-bond
correlations observed from H-8a 8 2.49 to C-5 at 8 92.3 and C-13 at 8 54.8 suggested H-8
was in a pseudo equatorial orientation, which required H-8a up-face. A network of HMBC
correlations such as H-5 at 5 5.03 to C-6, C-7, C-8, C-4, C-12, and C-15, plus with assistance
of other 2-D experiments of COSY, HSQC, and TOCSY, completed the structure
assignments for compound la as shown in Scheme B below. The 1H and 13C NMR chemical
shifts were recorded from ID NMR experiments and referenced to normal methanol signals
at 8 3.35 and 49.15 for proton and carbon, respectively.


[0081] The orientation of the carboxylic group (attached to C-6) was determined to be up
on the basis of ROESY data and three-bond HMBC correlations (see Scheme C below). The
ROESY data demonstrated that H-10eq at δ 3.82 was in P-orientation (up-face) as it was
coupled to H-17 at 6 4.08. The a-oriented proton H-10ax at S 3.09 was correlated to H-8b at 8
1.64, indicating H-8b was in the same face of H-l0ax. The proton H-8b showed strong HMBC
coupling to the carboxylic carbon C7, revealing the anti coplanar relationship.

B. Mass Spectrum Analysis:
[0082] MS spectrum showed the molecular ion of m/z 388 and the unique fragment of
m/z 344 due to losing a CO2 group, revealing the presence of the carboxylic moiety. The
measured accurate mass by adding two internal standards was 388.1750, corresponding to an
ionic formula of C21H26NO6 with experimental error of -0.4 mDa (~1.0 ppm). MS/MS
spectrum of m/z 388 peak was identical to the previous observed compound la peak in the
methylnaltrexone-saline sample. The fragmentation pattern is shown in Scheme D below.


C. X-rav Crystallography Analysis:
[0083] Compound 1-1 was recrystallized from ethanol/water by the following method.
30.5 mg of Compound 1-1 was dissolved at about 70 °C in a solution of 2 mL of ethanol and
0.5 mL of water. The resulting solution was allowed to cool to room temperature with the aid
of nitrogen gas. The resulting crystals were collected and dried overnight under vacuum at
40°C and subjected to X-ray powder diffraction analysis. The observed X-ray diffraction
peaks at 2 degrees theta are set forth in Table 1, below. The X-ray diffraction pattern as
compared with amorphous compound is depicted in Figure 1.

Example 2
Preparation of Compound la (Method A)
[0087] Methylnaltrexone (20 mg/mL) in 0.4 mg/mL of Ca EDTA, 0.65% NaCl, aqueous
solution was heated at 70°C for I week. Resulting solution was separated by HPLC analysis
as described in Example 1 above, yielding 1.55% of Compound la, RRT 0.79.

Preparation of Compound la (Method B)
[0088] Lyophilized methylnaltrexone was reconstituted with 10.6mL of normal saline, to
yield a concentration of 0.8 mg/mL of methylnaltrexone in a stoppered vial. A 13mm S2-
F451 RS D 777-1 RB2 bromobutyl stopper (Daikyo Seiko, Ltd) was removed from the vial,
cut in to 4 pieces then placed back into the specified vial. The vial containing solution and
stopper was then re-sealed with a stopper, and maintained at 40°C for 6 hours. Resulting
solution was separated by HPLC analysis as described in Example 1 above, yielding 2.13%
of Compound la, RRT 0.79.

Preparation of Compound la (Method C)
[0089] SeO2 (9.00 g, 81.1 mmol) was added to an aqueous solution of methylnaltrexone
(17.50 g, 40.1 mmole in 360 mL) then heated to 97 °C with stirring until nearly all
methylnaltrexone was consumed. Given reaction mixture was cooled to ambient temperature

and solid precipitates were filtered. The filter cake was washed with water and the wash
filtrates were combined with the reaction filtrate. NaOH (4.8 g, 120 mmol) was added to the
combined filtrates and stirred at ambient temperature until the reaction was complete. The
reaction mixture was concentrated then poured into a large volume of THF under agitation.
The resulting solids were partition into methanol, separated from the THF layer,
concentrated, poured into a large volume of Acetone under agitation, and filtered. The
filtrate was concentrated, diluted with acetone, then concentrated again several more times.
The final dilution was concentrated to dryness to afford a yellow solid which was washed
with acetone yielding 4.8g of Compound la (30% yield).

Example 5
Preparation of Compound la (Method D)
[0090] Methylnaltrexone (2.079 g) was dissolved in 2 L of 0.2M phosphate buffer pH
7.18. The resulting colorless solution was kept at 60°C for 114 days. The resulting solution
was separated by HPLC using the following HPLC method yielding 41% of Compound la,
RRT 0.79.


Example 6
Biological Activity Assays
A. Radioligand receptor binding assays
[0091] Compounds can be characterized in radioligand receptor binding assays, using
ligands that are specific for the mu, delta and kappa receptors. Binding assays may utilize
guinea pig brain membranes, human 293 cells, or stably transfected Chinese Hamster Ovary
(CHO) cells expressing each of the three opioid receptors. Such assays are known in the art,
and have been described, for example, in Martin, et al., J. Pharm. Exp. Ther., 301, 661-671
(2003); Zaki, et al., J. Pharm. Exp. Ther., 298, 1015-1020 (2002); Wentland, et al., J. Med.
Chem., 46, 838-849 (2003) and Neumeyer, et al., J. Med. Chem. 43:114 (2000).
[0092] For example, membranes can be isolated from CHO cells that stably express
either the human mu, delta or kappa opioid receptor. At approximately 80% confluence, cells
are harvested using a cell scraper. Cells and media from plates are centrifuged at 200xg for
10 min at 4° C, then resuspended in 50 mM Tris-HCl, pH 7.5. Cells are then homogenized
by use of a Polytron; centrifuged at 48,000xg for 20 min at 4° C, then resuspended in 50 mM
Tris-HCl, pH 7.5, at an estimated final protein concentration of 5-10 mg/ml, as determined by
the Bradford method. Prepared membranes may be stored, at -80° C. until use. Alternatively,
guinea pig brain membranes can be prepared and used as previously described in Neumeyer,
et al., J. Med. Chem. 43:114 (2000).
[0093] For assays, cell membranes are incubated at 25° C. with radiolabeled ligand in a
final volume of 1 ml of 50 mM Tris-HCl, pH 7.5. Ligands for each of mu, kappa, and delta
are known in the art. Any suitable ligand may be used, including, for example, a mu-
selective peptide (e.g., DAMGO) may be selected for use in assays, as well as a kappa
selective ligand (e.g., U69.593), and a delta selective ligand (e.g., naltrindole). Incubation
times of about 60 minutes are used for the mu-selective peptide [3H]DAMGO and the kappa-
selective ligand [3H]U69,593, and about 4 hours of incubation for the delta-selective
antagonist [3H]naltrindole. Nonspecific binding is measured by inclusion of a non-selective
ligand (e.g., 1 uM naloxone). Binding can be terminated by filtering the samples through
filters and washing filters. For example, binding assays may be passed through Schleicher &
Scheull No. 32 glass fiber filters using a Brandel 48-well cell harvester. Filters are
subsequently washed three times with 3 ml of cold 50 mM Tris-HCl, pH 7.5, and can be
counted in 2 ml of Ecoscint A scintillation fluid. For [3H]U69,593 binding, filters are soaked
in 0.1% polyethylenimine for at least 30 minutes before use.

[0094] IC50 values can be calculated by a least squares fit to a logarithm-probit analysis.
Ki values of unlabeled compounds are calculated from the equation Ki=(IC.sub.50)/1+S
where S=(concentration of radioligand) (Kd of radioligand). Cheng and Prusoff, Biochem.
Pharmacol. 22:3099 (1973).
B. 35S GTPγS Binding Assays.
[0095] Membranes from CHO cell lines expressing either mu, delta or kappa receptor, are
incubated with various concentrations of each opioid for 60 minutes at 30°C. in a final
volume of 0.5 ml of assay buffer (50 mM Tris-HCl, 3 mM MgCl.sub.2, 0.2 mM EGTA, 100
mM NaCl, pH 7.5) containing 3 μM GDP and 0.08 nM 35S GTPγS. Basal binding activity
can be determined in the presence of GDP and the absence of opioids; and nonspecific
binding can be determined by including 10 uM unlabeled 35S GTPγS. Incubation can be
terminated by filtration under vacuum through glass fiber filters, followed by washes with 3
ml ice-cold 50 mM Tris-HCl, pH 7.5. Samples can be allowed to equilibrate overnight and
counted in 2 ml Ecoscint A scintillation fluid for 2 minutes in a liquid scintillation counter.
[0096] For 35S GTPγS binding assays, percent stimulation of 35S GTPγS binding is
defined as [(opioid-stimulated binding-basal binding) basal binding] X 100% stimulation is
plotted as a function of opioid concentration (log scale). EC50 and Emax values are
determined by linear regression analysis. All data may be compared across conditions using,
for example, ANOVA and non-paired two-tailed Student's tests.
C. Tail flick Assay.
[0097] The thermal nociceptive stimulus can be 55°C. water with the latency to tail flick
or withdrawal taken as the endpoint. McLaughlin et al., J. Pharmacol. Exp. Ther. 289:304
(1999); McLaughlin et al., Eur. J. Pharmacol. 320:121 (1997); Neumeyer, et al., J. Med.
Chem. 43:114 (2000); and Xu et al., J. Pharmacol. Exp. Ther. 279:539 (1996).
Intracerebroventricular (i.c.v.) injections are made directly into the lateral ventricle. A mouse
is lightly anesthetized with ether, an incision is made in the scalp, and the injection is made 2
mm lateral and 2 mm caudal to bregma at a depth of 3 mm using a 10 μl Hamilton microliter
syringe. The volume of all i.c.v. injections are about 5 ul. After determining control latencies,
the mouse receives graded i.c.v. doses of opioid agonists or antagonists at various times.
When measuring agonist activity, selective antagonists, .beta.-FNA (mu), ICI 174,864 (delta)
and/or-BNI (kappa) can be used as previously described. McLaughlin et al., J. Pharmacol.
Exp. Ther. 289:304 (1999). When measuring antagonist activity, morphine, DPDPE, and

U50.488 are co-administered with the new compounds as a single i.c.v. injection, with testing
taking place 20 mm after the injection. A cut-off time of 15 seconds is used; if the mouse
fails to display a tail flick, the tail is removed from the water and that animal can be assigned
a maximal antinociceptive score of 100%. Mice showing no response within 5 seconds in the
initial control test are eliminated from the experiment. Antinociception at each time point can
be calculated according to the following formula: % antinociception=100X(test latency-
control latency)/(15-control latency).
[0098] Antagonist activity can be determined by calculating the pA2 values for a
compound. For example, a morphine dose-response curve is generated. Then morphine and
antagonist is co-injected and the morphine dose-response curve is generated in the presence
of varying doses of the antagonist. The tail flick test can be used to characterize both mu and
delta opioid receptor agonist and antagonist activity.
D. Writhing Assay.
[0099] Because antinociception induced by kappa opioid agonists has been difficult to
evaluate in the tail flick test, the action of the compounds can be determined in the mouse
acetic-acid writhing test. After receiving i.c.v. doses of opioid agonists and antagonists at
various times, an i.p. injection of 0.6% acetic acid (10 ml/kg) are administered to each mouse.
Five minutes after administration, the number of writhing signs displayed by each mouse are
counted for an additional 5 minutes. Antinociception for each tested mouse can be calculated
by comparing the test group to a control group in which mice were treated with i.c.v. vehicle
solution.
E. Neurotransmitter Assay
[00100] Results from the neurotransmitter assay for Compound la are set forth in Table 3
and depicted in Figure 3.


F. Opioid Functional Antagonist Assay
[00101] The opioid functional antagonist assay was performed as described in Coward P,
Chan SD, Wada HG, Humphries GM, Conklin BR.(1999) and Chimeric G proteins allow a
high-throughput signaling assay of G-coupled receptors. An. Biochem. 270(2): 242-8 (1999).
Specifically, the assay was performed as follows.
1. Cells were grown to confluence in 96-well plates, washed physiological buffer
was added before analysis.
2. Cells were loaded with dye that measures intracellular calcium.
3. Agent or CTOP was added to cells.
4. fluorescence was measured at 485nm excitation / 525nm emission every 3
seconds for at least 20 seconds.
5. Cells were activated using 10 nM DAMGO agonist.
6. Fluorescence was measured for 60 seconds more.
[00102] The cells used were CHO cells that express human recombinant Mu opioid
receptors, DAMGO agonist is a peptide with the amino acid sequence Tyr-D-Ala-Gly-N-
methyl-Phe-Gly-ol, and CTOP is a peptide with the amino acid sequence D-Phe-Cys-Tyr-D-
Trp-Orn-Thr-Pen-Thr amide (disulfide bridge 2-7).
[00103] The opioid functional antagonist assay is characterized as measuring calcium
levels where 0% (basal) was 350 nM calcium and 100% (maximum, 10 nM DAMGO) was
3000 nM calcium.
[00104] Results of the opioid functional (calcium) antagonist assay for Compound la are
set forth in Table 4-1 and Table 4-2. Dose response curves for Compound la compared with
naloxone and CTOP are depicted in Figure 4.



G. Administration in Gl-Physiology altered Dogs.
[00105] A 50 mg capsule formulation of Compound la was screened in gastrointestinal
(GI) physiology regulated male beagle dogs. Atropine (~ 20 μg/kg; IV) and pentagastrin (~
10 μg/kg; IM) were administered 15 minutes prior to formulation administration and another
dose of pentagastrin (10 μg/kg; IM) was administered 30 minutes post dose. Atropine slows
down canine GI motility and pentagastrin decreases pH resulting in GI conditions almost
similar to that of humans. The capsules (50 mg Compound la) were dosed to six dogs (9.4 —
13.7 kg) via oral administration following an overnight fast and blood samples were drawn at
0 (predose), 0.5, 1, 2, 3,4, 6, 8, 12, 24 and 48 hours after dosing; plasma was separated and
assayed for Compound la content. All dogs were fed 4 hours post dose.
[00106] 50 mg Compound la capsule contained neat 51.5 mg of Compound la 97% purity
(50 mg of Compound la), filled in #AA-DB HGC Swedish orange capsule.
[00107] Bioanalytical results were received and a preliminary PK assessment was
performed. Individual dog plasma Compound la concentration-time profiles were subjected
to noncompartmental pharmacokinetic analyses (WinNonlin, Model 200). The following
pharmacokinetic parameters were determined for each dog, and descriptive statistics were
calculated: AUC, Cmax, and tmax- The results are summarized in Table 5 below.


[00108] One skilled in the art will readily ascertain the essential characteristics of the
invention, and understand that the foregoing description and examples are illustrative of
practicing the provided invention. Those skilled in the art will be able to ascertain using no
more than routine experimentation, many variations of the detail presented herein may be
made to the specific embodiments of the invention described herein without departing from
the spirit and scope of the present invention.
[00109] Patents, patent applications, publications, and the like are cited throughout the
application. The disclosures of each of these documents are incorporated herein by reference
in their entirety.

CLAIMS
What is claimed is:
1. A compound of formula I:

2. The compound according to claim 1, wherein said compound is:

3. A compound as claimed in claim 1 or claim 2, wherein said compound is a
pharmaceutically acceptable salt and in solid form.
4. A compound as claimed in any one of claims 1-3, wherein said compound is a
pharmaceutically acceptable salt selected from the group consisting of a chloride, sulfate,
bisulfate, hydroxyl, tartrate, nitrate, citrate, bitartrate, carbonate, phosphate, malate, maleate,
bromide, iodide, fluoride, fumarate sulfonate, methylsulfonate, formate, carboxylate, sulfate,
methylsulfate and succinate.
5. A compound of formula la:


wherein X" is a suitable anion other than trifluoroacetate.
6. A compound as claimed in claim S, wherein X" is selected from the group
consisting of a chloride, sulfate, bisulfate, hydroxyl, tartrate, nitrate, citrate, bitartrate,
carbonate, phosphate, malate, maleate, bromide, iodide, fluoride, fumarate sulfonate,
methylsulfonate, formate, carboxylate, sulfate, methylsulfate and succinate.
7. A compound as claimed in claim 5 or claim 6, wherein the compound is in a
solid form.
8. A compound as claimed in claim 5 or claim 6, wherein the compound is in
solution.
9. A pharmaceutically acceptable composition comprising a therapeutically
effective amount of a compound as claimed in any one of claims 1-8, and a pharmaceutically
acceptable carrier.
10. A composition as claimed in claim 9, formulated for administration to a
human subject.
11. A composition as claimed in claim 9 or claim 10, further comprising
methylnaltrexone.
12. A method of reducing one or more side effects of opioid therapy in a subject
receiving opioid treatment comprising administering to the subject a composition according
to claim 9.
13. The method according to claim 12, characterized in that the side effect is
caused, mediated, or exacerbated by opioid receptor activity.
14. A method for reducing one of more effects of endogenous opioid activity in a
subject comprising administering to the subject the composition according to claim 9.

15. The method according to claim 14, characterized in that the side effect is
caused, mediated, or exacerbated by opioid receptor activity.
16. A method of reducing one or more side effects of opioid therapy in a subject
receiving opioid treatment comprising administering to the subject an effective amount of the
composition of claim 4.
17. The method of claim 12, wherein the side effect affected by treatment
comprises at least one effect selected from inhibition of intestinal motility, gastrointestinal
dysfunction, constipation, bowel hypomotility, impaction, gastric hypomotility, GI sphincter
constriction, increased sphincter tone, inhibition of gastrointestinal motility, inhibition of
gastric emptying, delayed gastric emptying, incomplete evacuation, nausea, emesis,
cutaneous flushing, bloating, abdominal distension, sweating, dysphoria, pruritis, and urinary
retention.
18. The method of claim 12, wherein the subject is a patient receiving short term
opioid administration or a patient receiving chronic opioid administration.
19. The method of claim 14, wherein the effect affected by treatment comprises at
least one condition or disorder selected from ileus, post-operative ileus, paralytic ileus, post-
partum ileus, gastrointestinal dysfunction developing following abdominal surgery, and
idiopathic constipation.
20. A method of treatment of a disorder mediated by opioid receptor activity in a
subject comprising administering to the subject the composition of claim 9, wherein the
disorder is selected from the group consisting of a cancer involving angiogenesis, an
inflammatory disorder, immune suppression, a cardiovascular disorder, chronic
inflammation, chronic pain, sickle cell anemia, a vascular wound, retinopathy, decreased
biliary secretion, decreased pancreatic secretion, biliary spasm, and increased
gastroesophageal reflux.
21. A method of treatment of a dopamine dysregulation disorder in a subject
comprising administering to the subject an effective amount of the composition according to
claim 9, wherein the disorder is selected from the group consisting of schizophrenia, attention

deficit hyperactivity disorder (ADHD), attention deficit disorder (ADD), Parkinson's disease,
hyperprolactinemia, depression, and addiction disorders.
22. A method of treatment of a subject for a dependence or addiction disorder
comprising administering to the subject an effective amount of the composition according to
claim 9.
23. The method of claim 22, wherein the dependence or addiction disorder is
selected from the group consisting of narcotic dependence or addiction, alcohol dependence
or addiction, nicotine dependence or addiction; and behavioral dependence or addiction.
24. Use of a compound as claimed in any one of claims 1 -8 in the manufacture of
a medicament for reducing one or more side effects of opioid therapy in a subject receiving
opioid treatment.
25. Use as claimed in claim 24, wherein the side effect is caused, mediated, or
exacerbated by opioid receptor activity.
26. Use of a compound as claimed in any one of claims 1-8 in the manufacture of
a medicament for reducing one of more effects of endogenous opioid activity in a subject.
27. Use as claimed in claim 26, wherein the effect is caused, mediated, or
exacerbated by opioid receptor activity.
28. Use as claimed in claim 24 or claim 25, wherein said side effect comprises at
least one effect selected from inhibition of intestinal motility, gastrointestinal dysfunction,
constipation, bowel hypomotility, impaction, gastric hypomotility, GI sphincter constriction,
increased sphincter tone, inhibition of gastrointestinal motility, inhibition of gastric emptying,
delayed gastric emptying, incomplete evacuation, nausea, emesis, cutaneous flushing,
bloating, abdominal distension, sweating, dysphoria, pruritis, and urinary retention.
29. Use as claimed in any one of claims 24-28, wherein the subject is a patient
receiving short term opioid administration.

30. Use as claimed in any one of claims 24-28, wherein the subject is a patient
receiving chronic opioid administration.
31. Use as claimed claim 26 or claim 27, wherein the effect comprises at least one
condition or disorder selected from ileus, post-operative ileus, paralytic ileus, post-partum
ileus, gastrointestinal dysfunction developing following abdominal surgery, and idiopathic
constipation.
32. Use of a compound as claimed in any one of claims 1-8 in the manufacture of
a medicament for the treatment of a disorder mediated by opioid receptor activity in a subject,
wherein the disorder is selected from the group consisting of a cancer involving angiogenesis,
an inflammatory disorder, immune suppression, a cardiovascular disorder, chronic
inflammation, chronic pain, sickle cell anemia, a vascular wound, retinopathy, decreased
biliary secretion, decreased pancreatic secretion, biliary spasm, and increased
gastroesophageal reflux.
33. Use of a compound as claimed in any one of claims 1-8 in the manufacture of
a medicament for the treatment of a disorder mediated by opioid receptor activity in a
subject,, wherein the disorder is selected from the group consisting of schizophrenia,
attention deficit hyperactivity disorder (ADHD), attention deficit disorder (ADD),
Parkinson's disease, hyperprolactinemia, depression, and addiction disorders.
34. Use of a compound as claimed in any one of claims 1-8 in the manufacture of
a medicament for the treatment of a dependence or addiction disorder.
35. Use as claimed in claim 34, wherein the dependence or addiction disorder is
selected from the group consisting of narcotic dependence or addiction, alcohol dependence
or addiction, nicotine dependence or addiction; and behavioral dependence or addiction.

The present invention relates to compounds of formula I, synthesis thereof, and methods of using the same, as
antagonists of opioid receptors.