SUSTAINED RELEASE COMPOSITIONS
Field of the Invention
The present invention relates to sustained release compositions comprising plurality of
sustained release beads. Particularly the sustained release beads comprise coated drugresin
complexes comprising drug-resin complexes of at least one active agent and at
least one ion-exchange resin; coated with at least one release modifier. The invention
further relates to preparation of such sustained release compositions in the form of liquid
suspensions, tablets, capsules, orally disintegrating tablets, dispersible tablets and the
like.
Background of the Invention
The advantages of sustained release formulations are well known in the pharmaceutical
field. These include the ability of the given pharmaceutical preparation to maintain a
desired therapeutic effect over a comparatively longer period of time, reduced side
effects, etc. Moreover, for drugs having a short elimination half-life, less frequent
administration and better patient compliance may be obtained with sustained release
preparations as compared to the conventional dosage forms.
Dextromethorphan is one of the most widely used antitussives for the treatment of cough
associated with acute upper respiratory tract infection. It has an opioid-like structure and
being the D-isomer of codeine analog, exerts its pharmacologic action in the same way
as L-isomer; but lacks analgesic and addictive properties thereof when used at
recommended doses. Dextromethorphan acts centrally to relieve cough, is active against
dry cough and does not exhibit significant expectorant properties for productive cough.
Dextromethorphan is rapidly absorbed from the gastrointestinal tract and peak plasma
concentrations are reached in approximately 2.5 hours. The plasma elimination half-life
of dextromethorphan is 1.2 to 3.9 hours. Dextromethorphan is widely distributed, and is
rapidly and extensively metabolized by the liver. The maximum time of effectiveness of
dextromethorphan in conventional compositions is therefore only a few hours.
Consequently, repeated dosages must be taken at frequent intervals to obtain long term
therapeutic levels of drug. The usual doses for immediate-release formulations range
from 2.5 - 30 mg 3 - 4 times a day. After high initial peak concentrations, the level of drug
in the blood stream constantly decreases because of the biological elimination, so that
there is little or no therapeutic effect at the end of the period between dosages. As a
result, the therapeutic effect fluctuates between dosages resulting in peaks and troughs
in the level of drug in the blood. Multiple dosing also often results in poor patient
compliance and inefficient therapy
Development of sustained release formulation of active agents such as
dextromethorphan that release the drug at a predetermined rate to maintain a desired
therapeutic effect over a comparatively longer period of time with reduced side effects
thereby increasing patient compliance, minimizing peak-trough fluctuations and
improving effectiveness of the medication are therefore particularly desirable. Further
sustained release compositions can also reduce night-time coughing, eliminate need to
interrupt sleep to take medication and prevent missed doses thereby increasing patient
convenience.
Ion-exchange is known to have utility in providing improved drug delivery systems for
orally administered drug products. U.S. Patent No. 2,990,332 discloses drug-resin
complexes prepared by interaction of cationic ion-exchange resins with basic drugs in
their cationic form, such as amphetamine and codeine. Drug-resin complexes thus
offered a method for retarding the rate of drug release not available using conventional
drug delivery systems. However the degree of control of drug release from drug-resin
complexes was found to be unsatisfactory since for many drugs only a relatively short
delay in drug release was obtained. Sustained release was difficult to achieve with such
uncoated drug-resin complexes due to many variables such as variation in particle size
and cross-linkage in the resin used as well as patient to patient variability in the ionic
strength and pH of the gastrointestinal fluids that determine the release of the drug from
the drug resin complex.
Attempts were therefore made to coat drug-resin complexes so as to provide a further
diffusion barrier to drug release and thereby offer greater control over the drug release
profile. Various coated drug-ion exchange resin complexes have been reported in U.S.
Patent Nos. 3 ,138,525, 3,499,960 and 3,594,470, but none provide desired sustained
release profile as obtainable with the present invention. Moreover such coated drug-resin
complexes when suspended in liquid dosage forms or upon contact with gastrointestinal
fluids, resulted in rupturing of the diffusion barrier coating due to swelling of the resin
leading to loss of control of drug release.
U.S. Patent No. 4,22 1,778 discloses a range of drug-resin complexes coated with a
water-permeable diffusion barrier coating such as ethylcellulose. The use of a solvating
agent such as PEG 4000 has also been described therein which minimizes the tendency
of drug ion exchange resin complex particles to swell and fracture the barrier coatings in
biological fluids. Further, U.S. Patent No. 4,996,047 describes using drug content above
a specified value in the drug-ion exchange resin complex to avoid the swelling of the
drug-ion exchange resin complex and thereby minimizing the rupture of the coating and
avoiding the need to use a solvating agent. U.S. Patent No. 5,368,852 discloses that
despite the use of impregnating agents, certain preservatives used in the liquid
preparations containing coated drug-resin complexes tend to cause rupture of the
diffusion barrier coating of the drug-ion exchange resin complex. Such a rupturing of the
coating membrane is disclosed to be avoided first by use of a specific diffusion barrier
film material, i.e. ethyl cellulose having a specific content of ethoxyl group, and secondly
by adding the specific preservative at a specific concentration to control the release of
the drug.
Further various attempts have been made to provide sustained release compositions of
active agents comprising either drug-resin complexes coated at a single barrier coating
level or combinations thereof with uncoated drug-resin complexes. U.S. Patent No.
6,001 ,392 discloses sustained release composition comprising a mixture of coated and
un-cqated drug-resin complexes. About 20 to about 80% of the drug-resin complexes are
said to be coated with a mixture of ethyl cellulose or ethyl cellulose latexes with
plasticizers and water dispersible polymers. U.S. Publication No. 2008/01 18570
discloses a coated drug/resin complex that comprises drug-resin complexes and a
substantially plasticizer-free coating layer of a methacrylate polymer preferably Eudragit
NE-30D applied at least substantially around a portion of the resin forms to control the
release rate of the drug. Suspension dosage forms comprising either completely coated
drug-resin complexes coated at a single level or comprising a portion of un-coated and a
portion of coated drug-resin complexes have been described herein. Further, U.S.
Publication No. 2007/021 551 1 discloses a coated drug-ion exchange resin matrix useful
in preparing modified release formulations, comprising a drug-ion exchange resin
complex and a water-insoluble release retardant which forms a drug-resin matrix and a
cured water-permeable, high tensile strength, water-insoluble, barrier coating comprising
a non-ionic polymer such as Kollicoat SR 30D and a plasticizer. These compositions are
said to provide prolonged, programmable release of drugs from the drug-resin
complexes of up to about 24 hours.
Since the drug release kinetics from ion exchange resins is dependent on the pH and
ionic strength of the fluid of the gastrointestinal tract that varies from patient to patient,
the presence of uncoated drug-resin complexes along with coated drug-resin complexes
can result in high initial release of the drug from the uncoated drug-resin complexes
causing dose dumping and related adverse effects. Additionally, if the sustained release
compositions comprise drug-resin complexes that are coated by single level of barrier
coating i.e. the entire portion of drug-resin complexes are coated with a barrier diffusion
coating to up to for e.g. say 20% or say 30% by weight of the drug-resin complex, then
excessive retardation of drug release may be observed and in such instances the
percentage of drug released from the coated complexes may be incomplete and
substantial amount of the drug may remain bound within the coated drug-resin
complexes.
A need therefore exists to provide sustained release compositions comprising sustained
release beads that comprise coated drug-resin complexes wherein the release of active
agent from the beads does not result in dose dumping or high initial burst nor does it
result in excessive release retardation or incomplete release of the drug from the
composition. The present inventors after rigorous experimentation have found that
sustained release compositions comprising sustained release beads that comprise only
coated drug-resin complexes comprising drug-resin complexes of at least one active
agent and at least one ion-exchange resin; coated with at least one release modifier;
wherein the drug-resin complexes are variably coated at different levels of barrier coating
of release modifier and wherein the variably coated drug-resin complexes are present in
particular proportions, can help achieve sustained release profiles that do not result
either in dose dumping or excessive release retardation while providing desired in-vitro
drug release profile and bioavailability. The sustained release compositions according to
the present invention thus provide release of the active agent at a predetermined rate
thereby avoiding too quick a release of the drug and too high peaks of the blood or tissue
levels, which can lead to undesirable side effects while also avoiding incomplete release
of the drug from the sustained release composition.
Summary of the Invention
The present invention relates to sustained release compositions comprising plurality of
sustained release beads comprising coated drug-resin complexes comprising (a) drugresin
complexes comprising at least one active agent and at least one ion-exchange
resin; and (b) release modifier coating.
Detailed Description of the Invention
The present invention relates to sustained release compositions comprising plurality of
sustained release beads. Particularly the sustained release beads comprise coated drugresin
complexes comprising drug-resin complexes of at least one active agent and at
least one ion-exchange resin; coated with at least one release modifier.
Active agents
The term "active agent/s", as employed herein refers to any suitable drug that is capable
of complexation with an ion exchange resin, and for which controlled release is desired.
In general all, including, but not limited to, acidic, basic, or amphoteric drugs, especially
those having short biological half-lives in the order of up to about 12 hours are potential
candidates in the compositions of the present invention.
Active agents that can be included in the drug-resin complexes of the present invention
include, but are not limited to, one or more analgesics such as, but not limited to, aspirin,
codeine, morphine, dihydromorphone, oxycodone, hydrocodone and the like;
antihistamines such as, but not limited to, dimenhydrinate, diphenhydramine,
chlorpheniramine, brompheniramine, dexchlorpheniramine, hydroxyzine,
dexbrompheniramine, fexofenadine, terfenadine, cetirizine, levocetirizine and the like;
expectorants or mucolytics such as, but not limited to, ambroxol, bromhexine,
carbocisteine, domiodol, guaifenesin and the like; anti-tussive agents such as, but not
limited to, codeine, dextromethorphan, hydrocodone and the like; decongestants such
as, but not limited to, phenylephrine, pseudoephedrine and the like; analeptic agents;
anesthetic agents; anti-asthmatics such as, but not limited to, theophylline and the like;
anti-arthritic agents; anti-cancer agents; anti-cholinergic agents; anti-convulsant agents
such as, but not limited to, phenobarbital sodium, phenytoin sodium, valproate sodium
barbiturates, amylobarbitone sodium, butabarbital sodium, secobarbital sodium and the
like; anti-depressant agents; antidiabetics; anti-helminthic agents; anti-diarrheal agents;
anti-epileptics such as, but not limited to, phenytoin, meprobamate, nitrezepam and the
like; anti-hyperlipidemic agents; antihypertensives such as, but not limited to, clonidine,
methyldopa; captopril and the like; antihypotensives such as, but not limited to,
propranolol, clonidine and the like; anti-infective agents; anti-inflammatory agents; nonsteroidal
anti-inflammatory agents such as, but not limited to, naproxyn, diclofenac,
indomethacin, ibuprofen, sulindac, meclofenamate sodium, tolmetin sodium and the like;
anti-emetics such as, but not limited to, metoclopramide and the like; anti-migraine
agents; anti-neoplastic agents; anti-tubercular agents; antibiotics such as, but not limited
to, tetracyclines and the like; antacids; antiulcer agents; anti-Parkinsonism drugs; antipruritic
agents; antipsychotic agents; anti-pyretic agents; anti-spasmodics such as, but
not limited, atropine, scopolamine and the like; anti-viral agents; anxiolytic agents;
appetite suppressants; attention deficit hyperactivity disorder treating agents,
cardiovascular agents including, but not limited to, calcium channel blockers, antianginal
agents; central nervous system agents; beta-blockers; antiarrhythmic agents;
bronchodilators such as, but not limited to, albuterol; central nervous system stimulants;
diuretics such as, but not limited to, ethacrynic acid, bendrofluazide and the like; genetic
materials; hormonolytics; hypnotics; hypercalcemics; hypoglycemic agents;
immunosuppressive agents; antimuscarinics; genitourinary smooth muscle relaxants;
beta-agonists; narcotic antagonists; nicotine; nutritional agents; parasympatholytics;
peptide drugs; antihemorrhoidals; psychostimulants; psychotropics; mucolytics;
sedatives; laxatives; vitamins; sialagogues, steroids; sympathomimetics; tranquilizers;
vasodilators such as, but not limited to, nifedipine, papaverine, diltiazem, nicardirine and
the like; or combinations thereof. The active agent/s employed in the compositions of the
present invention may be in the form of free base or acid or pharmaceutically acceptable
salts, prodrugs, active metabolites, polymorphs, solvates, hydrates, enantiomers, optical
isomers, tautomers or racemic mixtures thereof.
The term "anti-tussive agents", as employed herein refers to any compound that can be
employed for the treatment, management or mitigation of cough, cold, cold-like and/or flu
symptoms and the discomfort, pain, headache, fever and general malaise associated
therewith. Suitable anti-tussives that can be incorporated in the compositions of the
present invention include, but are not limited to, dextromethorphan, diphenhydramine,
caramiphen, carbapentane, ethylmorphine, noscapine, codeine, hydrocodone, and the
like or combinations thereof. Furthermore the anti-tussive drugs that are suitable for use
in the preparations of the present invention are acidic, amphoteric or basic in nature. The
anti-tussive agents employed in the compositions of the present invention may be in the
form of free base or acid or pharmaceutically acceptable salts, prodrugs, active
metabolites, polymorphs, solvates, hydrates, enantiomers, optical isomers, tautomers or
racemic mixtures thereof.
In one embodiment the active agent employed in the composition is an anti-tussive
agent. In another embodiment the anti-tussive agent employed in the present invention is
dextromethorphan in the form of free base or its pharmaceutically acceptable salts,
prodrugs, polymorphs, solvates, hydrates, active metabolites, enantiomers, optical
isomers, tautomers or racemic mixtures. In one embodiment, the anti-tussive agent
employed in the compositions of the present invention is dextromethorphan
hydrobromide.
Further suitable antihistamines that can be incorporated in the compositions of the
present invention include, but are not limited to, dimenhydrinate, diphenhydramine,
chlorpheniramine, brompheniramine, dexchlorpheniramine, hydroxyzine,
dexbrompheniramine, fexofenadine, terfenadine, cetirizine, levocetirizine and the like or
combinations thereof. Furthermore the antihistamines suitable for use in the preparations
of the present invention are acidic, amphoteric or basic in nature. The antihistamines
employed in the compositions of the present invention may be in the form of free base or
acid or pharmaceutically acceptable salts, prodrugs, active metabolites, polymorphs,
solvates, hydrates, enantiomers, optical isomers, tautomers or racemic mixtures thereof.
In one embodiment the active agent delivered by the sustained release composition of
the present invention include, but are not limited to, dextromethorphan, hydrocodone,
chlorpheniramine, phenylephrine, pseudoephedrine, codeine, morphine,
dihydromorphone, oxycodone, dimenhydrinate, diphenhydramine, brompheniramine,
cetirizine, levocetirizine, ambroxol, bromhexine, carbocisteine, domiodol, guaifenesin,
hydroxyzine, dexbrompheniramine, fexofenadine, terfenadine, dexchlorpheniramine or
combinations thereof in the form of free base, free acid, pharmaceutically acceptable
salt, prodrug, active metabolite, polymorph, solvate, hydrate, enantiomer, optical isomer,
tautomer or racemic mixture thereof.
Pharmaceutically effective amount of active agent is employed in the composition of the
present invention. The term "effective amount" refers to an amount effective to achieve
desired preventive, therapeutic and/or beneficial effect. In one embodiment the amount
of active agent in the composition can vary from about 0.01 weight % to about 85 weight
%, based on the total weight of the composition. In another embodiment the amount of
active agent in the composition can vary from about 0.02 weight % to about 75 weight %,
based on the total weight of the composition. In still another embodiment, the amount of
active agent in the composition can vary from about 0.05 weight % to about 60 weight %,
based on the total weight of the composition. In one embodiment the compositions of the
present invention may be administered at a dose of about 0.01 mg to about 200 mg of
anti-tussive agent or antihistamine. In another embodiment the compositions of the
present invention may be administered at a dose of about 0.1 mg to about 150 mg of
anti-tussive agent or antihistamine. In still another embodiment the compositions of the
present invention may be administered at a dose of about 0.5 mg to about 100 mg of
anti-tussive agent or antihistamine. In one embodiment the compositions of the present
invention may be administered at a dose of about 0.5 mg to about 100 mg of
dextromethorphan hydrobromide. In another embodiment the dose of dextromethorphan
hydrobromide is 30 mg. In another embodiment the compositions of the present
invention may be administered at a dose of about 0.5 mg to about 100 mg of
chlorpheniramine maleate. In another embodiment the dose of chlorpheniramine maleate
is 8 mg. In a further embodiment the compositions of the present invention may be
administered at a dose of about 0.5 mg to about 100 mg of hydrocodone bitartarate. In
another embodiment the dose of hydrocodone bitartarate is 10 mg.
Ion exchange resins
Active agent employed in the compositions of the present invention is complexed with at
least one ion exchange resin. Ion exchange resins suitable for compositions of the
present invention comprise a pharmacologically inert organic and/or inorganic matrix
containing functional groups that are ionic or capable of being ionized under the
appropriate conditions of pH. The organic matrix may be synthetic such as, but not
limited to, polymers or copolymers of acrylic acid, methacrylic acid, sulfonated styrene,
sulfonated divinylbenzene; or partially synthetic such as, but not limited to, modified
cellulose and dextrans. The inorganic matrix includes, but is not limited to, silica gel
modified by the addition of ionic groups. Covalently bound ionic groups may be strongly
acidic (e.g. , sulfonic acid, phosphoric acid), weakly acidic (e.g. , carboxylic acid), strongly
basic (e.g. , primary amine), weakly basic (e.g. quaternary ammonium), or a combination
of acidic and basic groups. The ion exchange resin having the polymeric matrix with an
anionic functional group is a cation exchange resin and that having a cationic functional
group is an anionic exchange resin. The mobile or exchangeable moieties depending on
the type of resin can be but not limiting to sodium, hydrogen, potassium, chloride and the
like.
In one embodiment of the present invention ion exchange resin employed is a cation
exchange resin or an anion exchange resin or combination thereof. In a further
embodiment, cation exchange resin is employed for complexation with the active agent.
Non limiting examples of suitable cation exchange resin that may be employed include a
copolymer of methacrylic acid and divinylbenzene, sodium polystyrene sulfonate resin,
sulfonated copolymer of styrene and divinylbenzene, crosslinked polyacrylic acid resin,
polyacrylate resin, crosslinked carboxylic acid resin, crosslinked sulfonic acid resin,
crosslinked phosphonic acid resin, zeolite or a combination thereof.
In another embodiment, cation exchange resin that may be employed include, but are
not limited to, Amberlite ® IRP64 (porous copolymer of methacrylic acid and
divinylbenzene), Amberlite ® IRP69 (sodium polystyrene sulfonate or sulfonated
copolymer of styrene and divinylbenzene), Amberlite® IRP88 (cross linked polymer of
methacrylic acid and divinylbenzene), DOWEX® RTM. resins (strong cationic exchangers
based upon polystyrenesulphonic acid with variable crosslinking ( 1- 12%
divinylbenzene)), Tulsion® 335 - (Polacrilex/{Polacirilex S), Tulsion® 339 (Polacrilin
potassium USP), Tulsion® 344 (Sodium polystyrene sulfonate BP), Indion® 204
(crosslinked polyacrylic acid), Indion® 2 14 (crosslinked polyacrylic acid), Indion® 234
(crosslinked polyacrylic acid), Indion® 234S (crosslinked polyacrylic acid), Indion® 294
(crosslinked polyacrylic acid), Purolite® C 15 HMR (carboxylic acid functional group),
Purolite® C 115 E (carboxylic acid functional group), Purolite® C 100 HMR (sulfonic acid
functional group), Purolite® 100 MR (sulfonic acid functional group), polyacrylate resins,
cation exchange resins having phosphonic functional groups or zeolites. Cationic
exchange resins are selected for use with basic active agents and molecules having a
cationic functionality.
Other suitable ion-exchange resins include anion exchange resins, such as have been
described in the art and are commercially available.
The size of the ion-exchange particles that may be employed in the compositions of the
present invention may be from about 5 microns to about 750 microns. In one aspect the
particle size is within the range of about 40 microns to about 250 microns for liquid
dosage forms although particles up to about 1,000 micron can be used for solid dosage
forms, e.g., tables and capsules. Both regularly and irregularly shaped resin particles
may be employed in the present invention. Regularly shaped particles are those particles
that substantially conform to geometric shapes such as spherical, elliptical, and
cylindrical and the like, which are exemplified by Dow XYS-40010.00 and Dow XYS-
40013.00 (The Dow Chemical Company). Irregularly shaped particles are all particles not
considered to be regularly shaped, such as particles with amorphous shapes and
particles with increased surface areas due to surface channels or distortions. Irregularly
shaped ion-exchange resins of this type are exemplified by Amberlite IRP-69 (Rohm and
Haas).
In one embodiment, the ion exchange resin used in the compositions of the present
invention is sodium polystyrene sulfonate.
Drug-resin complexes
Drug-resin complexes according to the present invention comprise at least one active
agent and at least one ion-exchange resin. In one embodiment basic active agent is
complexed with cation exchange resin. In one embodiment anti-tussive agent is
complexed with ion-exchange resin. In another embodiment basic anti-tussive agent is
complexed with cation exchange resin. In still another embodiment dextromethorphan
hydrobromide is complexed with a cation exchange resin. In another embodiment, ant i
tussive agent is complexed with sodium polystyrene sulfonate. In another embodiment
dextromethorphan hydrobromide is complexed with sodium polystyrene sulfonate. In a
still another embodiment active agent can be complexed with ion exchange resin in any
ratio. In a further embodiment, ion exchange resin can be used for complexation with
active agent in a ratio of active agent to resin of about 1:0.1 to about 1:20. In another
embodiment, ion exchange resin can be used for complexation with active agent in a
ratio of active agent to resin of about 1:0.25 to about 1:10. In still another embodiment,
ion exchange resin can be used for complexation with active agent in a ratio of active
agent to resin of about 1:0.5 to about 1:5.
The drug-ion exchange resin complexes or drug-resin complexes can be prepared using
methods known in the art, such as, but not limiting to, blending, slurrying, kneading,
grinding, sieving, filling, compressing, lyophilization, spray-drying, fluid-bed drying or
centrifugal granulation. The drug-resin binding may be performed, for example, as a
batch or column process, as is known in the art. In one illustrative embodiment, drugresin
complex is prepared by batch process. In one embodiment the drug-resin
complexes were prepared by stirring aqueous slurry of drug and ion exchange resin for
about 0.5 hours to about 12 hours, followed by filtration and drying of the formed drugresin
complex.
In one embodiment, the invention relates to compositions comprising drug-resin
complexes having one or more active agents. In another embodiment, the invention also
relates to pharmaceutical compositions comprising drug-resin complexes wherein at
least one pharmaceutically acceptable excipient has been employed during the process
of preparation of the drug-resin complexes, such as, but not limited to, stabilizers and the
like to inhibit or prevent degradation of the drug-resin complex during manufacturing
process and over shelf life of the composition. Suitable stabilizers include, but are not
limited to, antioxidants, chelating agents or combinations thereof. In one embodiment,
stabilizer employed during the process of preparation of the drug-resin complexes is an
antioxidant. Any suitable antioxidant agent available to those of ordinary skill in the art
may be used. Antioxidant such as, but not limited to ascorbic acid, sodium
metabisulphite, potassium metabisulfite, sodium bisulfite, sodium sulfite, tocopherol,
sorbic acid, retinol, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT),
propyl gallate, sodium benzoate or any salt thereof, or a combination thereof may be
employed. Any suitable chelating agent known to those of ordinary skill in the art may be
used. Chelating agents such as, but not limited to, ethylene diaminetetraacetic acid
(EDTA), desferrioxamine B, deferoxamine, dithiocarb sodium, penicillamine, pentetate
calcium, a sodium salt of pentetic acid, succimer, trientine, nitrilotriacetic acid, transdiaminocyclohexanetetraacetic
acid (DCTA), diethylenetriaminepentaacetic acid,
bis(aminoethyl)glycolether-N,N,N',N'-tetraacetic acid, iminodiacetic acid, citric acid,
tartaric acid, fumaric acid, or any salt thereof, or a combination thereof may be
employed. The stabilizing agent can be present in a concentration of about 0.001% to
20% by weight of the composition and may or may not be in the final composition.
Further, the drug-resin complexes are impregnated with a solvating agent. The solvating
agent can be added as an ingredient in the resin drug complexation step or the drugresin
complexes can be treated with the solvating agent after complexing. This treatment
helps particles retain their geometry, and enables the effective application of barrier
coatings to the drug-resin complexes resulting in the ability to effectively prolong the
release of drugs from drug resin complexes. Solvating agent that can be employed in the
compositions of the present invention include, but are not limited to, polyethylene glycol,
propylene glycol, mannitol, lactose, methylcellulose, hydroxypropylmethylcellulose,
sorbitol, polyvinylpyrrolidone, carboxypolymethylene, xanthan gum, propylene glycol
alginate and combinations thereof. In one embodiment the solvating agent is
polyethylene glycol. In one embodiment, the drug-resin complexes may not be
impregnated with a solvating agent.
In an embodiment of the present invention along with the solvating agent, at least one or
more pharmaceutically acceptable excipients, such as but not limited to stabilizers may
be employed for impregnation of the drug-resin complexes. The stabilizers that may be
employed during impregnation of the drug-resin complexes include the ones as
described above under drug-resin complexes.
Release modifier coating
The release modifier coating comprises at least one release modifier. The drug-resin
complexes or impregnated drug-resin complexes are coated with a diffusion barrier
coating of at least one release modifier. The release modifiers that may be employed in
the compositions of the present invention include, but are not limited to, water-insoluble
release modifiers or water-soluble release modifiers or combinations thereof. The waterinsoluble
release modifiers that may be employed include polymeric water-insoluble
release modifier or non-polymeric water-insoluble release modifier or combinations
thereof.
Suitable polymeric water-insoluble release modifiers include, but are not limited to,
polyvinyl acetate, polyvinyl chloride, polyvinyl carbonate, ethyl cellulose, nitrocellulose,
vinylidene chloride-acrylonitrile copolymer, acrylonitrile-styrene copolymer, ethylene vinyl
acetate, cellulose acetate, cellulose acetate phthalate, cellulose acetate butyrate,
copolymers of vinyl pyrrolidone, blend of polymers comprising polyvinyl acetate,
hydroxypropylmethylcellulose phthalate, methacrylic acid copolymers such as Eudragit®
LI00/SI00/LI00-55 and the like or mixtures thereof; methacrylate copolymers such as
Eudragit® E100/EPO, Eudragit® RL100/RL30D/RLPO, Eudragit® RS100/RS30D/RSPO
and the like or mixtures thereof.
Suitable non-polymeric water-insoluble release modifiers include, but are not limited to,
fats, oils, waxes, fatty acids, fatty acid esters, glycerides, long chain monohydric alcohols
and their esters, phospholipids, terpenes or combinations thereof. The non-polymeric
water-insoluble release modifiers employed in the compostions of the present invention
include, but are not limited to, Cutina® (hydrogenated castor oil), Hydrobase®
(hydrogenated soybean oil), Castorwax® (hydrogenated castor -oil), Croduret®
(hydrogenated castor oil), Carbowax®, Compritol® (glyceryl behenate), Sterotex®
(hydrogenated cottonseed oil), Lubritab® (hydrogenated cottonseed oil), Apifil® (wax
yellow), Akofine® (hydrogenated cottonseed oil), Softisan® (hydrogenated palm oil),
Hydrocote® (hydrogenated soybean oil), Corona® (Lanolin), Gelucire®
(macrogolglycerides Lauriques), Precirol® (glyceryl palmitostearate), Emulcire™ (cetyl
alcohol), Plurol® diisostearique (polyglyceryl diisostearate), Geleol® (glyceryl
stearate),and mixtures thereof. In another embodiment, lipids or waxes can also be
employed in the form of an aqueous dispersion stabilized by surfactants and suitable
stabilizers.
Suitable water soluble release modifiers that may be employed include, but are not
limited to, polyvinylpyrrolidone, poloxamer, guar gum, xanthan gum, gum arabic,
tragacanthan, cellulose derivatives such as hydroxypropylmethylcellulose, hydroxypropyl
cellulose, methylcellulose, and hydroxyethyl cellulose, carboxymethylethyl cellulose,
hydroxyethylmethyl carboxymethyl cellulose, hydroxyethyl methyl cellulose,
carboxymethyl cellulose, methylhydroxyethyl cellulose, methylhydroxypropyl cellulose or
any mixtures thereof.
In one embodiment the release modifier employed is ethyl cellulose.
The release modifiers of the present invention may be used in admixture with at least
one pharmaceutically acceptable excipient, such as but not limited to, plasticizers,
pigments and the like or any mixtures thereof. Suitable plasticizers include, but are not
limited to, dibutyl sebacate, propylene glycol, polyethylene glycol, polyvinyl alcohol,
triethyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, tributyl citrate, triacetin or the
like or any combinations thereof. In an embodiment, the drug-resin complexes are
directly coated with the water-insoluble release modifier.
A coating procedure known to a person skilled in the art, which provides a substantially
complete coating on the impregnated drug-resin complexes without significant
agglomeration of the drug-resin complex particles, may be used. Coating to the drugresin
complexes may be applied using wet granulation, dry granulation, melt granulation,
melt coating, physical mixing, spray coating and the like. Coatings may be applied in a
coating pan or with a fluid-bed coating apparatus. The release modifier coatings may be
applied from aqueous suspension or organic solvents. Optionally after coating the coated
drug-resin complexes may be cured at a suitable temperature and for a suitable amount
of time.
In one embodiment, only coated drug-resin complexes are incorporated in the
compositions of the present invention. Optimum coat weight and coat thickness may be
determined for each drug-resin complex and generally depends on the drug release
characteristics of the resin for that particular active agent. In one embodiment the drugresin
complexes are variably coated at different levels of barrier coating of release
modifier and the variably coated drug-resin complexes are present in particular
proportions in the sustained release compositions. The presence of such variably coated
drug-resin complexes helps achieve the desired release profiles that does not result
either in dose dumping or excessive release retardation. In one embodiment the
compositions of the present invention comprise at least two variably coated populations
or portions of coated drug-resin complexes or the coated drug-resin complexes are
present in the form of at least two populations of variably coated drug-resin complexes.
In one embodiment drug resin particles may be coated from about 1% to about 75%
weight of the drug resin complexes. In another embodiment at least two populations of
variably coated drug-resin complexes are present in a ratio from about 1:99 to about
99:1. In one embodiment one portion or population of the drug-resin complexes are
coated with a barrier coating of at least one release modifier to up to about 25% by
weight of the drug-resin complex and at least another portion of the drug-resin
complexes are coated with a barrier coating of at least one release modifier to not less
than about 5% by weight of the drug-resin complex to provide desired in-vitro drug
release profile and bioavailability. In another embodiment one portion or population of
the drug-resin complexes are coated with a barrier coating of at least one release
modifier to up to about 15% by weight of the drug-resin complex and at least another
portion of the drug-resin complexes are coated with a barrier coating of at least one
release modifier to not less than about 15% by weight of the drug-resin complex to
provide desired in-vitro drug release profile and bioavailability. In a further embodiment,
the variably coated drug-resin complexes comprise at least one population of drug-resin
complexes coated with at least one release modifier from about 1% to about 25% by
weight of the drug-resin complex; and at least one population of drug-resin complexes
coated with at least one release modifier from about 5% to about 75% by weight of the
drug-resin complex. In a further embodiment, the variably coated drug-resin complexes
comprise at least one population of drug-resin complexes coated with at least one
release modifier from about 1% to about 25% by weight of the drug-resin complex; and
at least one population of drug-resin complexes coated with at least one release modifier
from about 5% to about 75% by weight of the drug-resin complex and are present in a
ratio from about 1:9 to about 9:1 in the total amount of the coated drug-resin complexes
employed in the compositions of the present invention. In a further embodiment, the
variably coated drug-resin complexes comprise at least one population of drug-resin
complexes coated with at least one release modifier from about 1% to about 15% by
weight of the drug-resin complex; and at least one population of drug-resin complexes
coated with at least one release modifier from about 5% to about 75% by weight of the
drug-resin complex. In another embodiment drug-resin complexes coated with a barrier
coating of at least one release modifier from about 1% to 15% by weight of the drug resin
complex and the drug-resin complexes coated with a barrier coating of at least of release
modifier to not less than about 15% by weight and not more than 75% by weight are
present in a ratio from about 1:9 to about 9:1 in the total amount of the coated drug-resin
complexes employed in the compositions of the present invention. In a further
embodiment drug-resin complexes coated with a barrier coating of at least one release
modifier from about 1% to 10% by weight of the drug resin complex and the drug-resin
complexes coated with a barrier coating of at least of release modifier to not less than
about 20% by weight and not more than 75% by weight are present in a ratio from about
1:9 to about 9:1 in the total amount of the coated drug-resin complexes employed in the
compositions of the present invention. The sustained release composition comprising
plurality of sustained release beads comprising coated drug-resin complexes comprising:
(a) drug-resin complex comprising at least one active agent and at least one ionexchange
resin; and (b) release modifier coating; wherein coated drug-resin complexes
are present in the form of at least two populations of variably coated drug-resin
complexes comprising at least one population of drug-resin complexes coated with at
least one release modifier from about 1% to about 25% by weight of the drug-resin
complex; and at least one population of drug-resin complexes coated with at least one
release modifier from about 5% to about 75% by weight of the drug-resin complex.
The coated drug-resin complexes may be present in the sustained release beads of the
present invention in an amount of from about 20% to about 100% by weight of the
beads.
Sustained release beads
Sustained release beads of the present invention comprise the coated drug-resin
complexes discussed above. In one embodiment the coated drug-resin complexes are
the sustained release beads. In another embodiment the sustained release beads
comprise coated drug-resin complexes and at least one pharmaceutically acceptable
excipient such as, but not limited to, diluents, stabilizers, release modifiers, or the like or
any combinations thereof. In one embodiment the sustained release beads of the
present invention comprise variably coated drug-resin complexes in particular
proportions as discussed under coated drug-resin complexes above. The compositions
of the present invention comprise one or more sustained release beads. The sustained
release beads employed in the present invention are in forms such as, but not limited to,
powder, particles, granules, pellets, beads, minitablets, tablets and the like or any
combinations thereof. The sustained release beads may be present in the compositions
in an amount from about 5% to about 95% by weight of the composition. In a further
embodiment the coated drug-resin complexes and/or sustained beads may be
overcoated using conventional polymers including, but not limited to, hydroxypropyl
methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, polyvinyl alcohol
polymethacrylates and the like or combinations thereof, waxes, and combinations
thereof; or using release modifiers listed above under release modifiers. In one
embodiment sustained release beads in the form of drug-resin complexes are
incorporated in the sustained release pharmaceutical compositions of the present
invention. The sustained release beads are incorporated in the sustained release
pharmaceutical compositions of the present invention by any of the methods generally
known to a person skilled in the art, especially depending on the form of the sustained
release beads being incorporated and the final form of the pharmaceutical composition.
Sustained release compositions
Sustained release pharmaceutical compositions of the present invention comprise
plurality of sustained release beads and at least one pharmaceutically acceptable
excipient. The sustained release compositions may be formulated for delivery of active
agent by any suitable route including, e.g. orally, topically, intraperitoneally,
transdermal^, sublingually, intramuscularly, transmucosally, rectally, subcutanoeulsly,
transnasally or via inhalation. In one embodiment, the sustained release compositions
are for oral delivery. The compositions for oral delivery may be in any form, such as, but
not limited to, liquid, solid or semi-solid preparations and the like. Liquid preparations for
oral administration may be in any form including, but not limited to, suspensions, syrups
or the like. Solid preparations for oral administration may be in any form including, but
not limited to, capsules, tablets, caplets, orally disintegrating tablets, dispersible tablets,
dry suspension for reconstitution, granules, wafers, bite-dispersion tablets and the like or
any combinations thereof. In one embodiment the sustained release preparation of the
present invention is a suspension.
The sustained release compositions of the present invention comprise at least one
pharmaceutically acceptable excipient, depending on the final dosage form to be
prepared, such as, but not limited to, binders, disintegrants, superdisintegrants, diluents,
salivating agents, surfactants, flavors, sweeteners, colorants, souring agents, viscolizers,
glidants, lubricants, solubilizers, stabilizers, suspending agents, preservatives,
cosolvents, anti-caking agents, buffers and the like or any combinations thereof.
Suitable disintegrants can be selected from, but not limiting to, crospovidone, calcium
silicate and starch. Suitable superdisintegrants include, but are not limited to, natural,
modified or pregelatinized starch, crospovidone, croscarmellose sodium, sodium starch
glycolate, low-substituted hydroxypropyl cellulose. Examples of suitable binders include,
but are not limited to, starch, pregelatinized starch, polyvinyl pyrrolidone, copovidone,
cellulose derivatives, such as hydroxypropylmethyl cellulose, hydroxypropyl cellulose
and carboxymethyl cellulose and their salts. Examples of suitable diluents include, but
are not limited to, starch, microcrystalline cellulose, lactose, xylitol, mannitol, maltose,
polyols, fructose, guar gum, sorbitol, magnesium hydroxide, dicalcium phosphate,
coprocessed mannitol and calcium silicate and the like or any combinations thereof.
Examples of lubricants include, but are not limited to, magnesium stearate, calcium
stearate, stearic acid, talc, and sodium stearyl fumarate. Suitable glidants includes but
are not limited to, colloidal silica, silica gel, precipitated silica, or combinations thereof.
Suitable salivating agents include, but are not limited to, micronised polyethylene glycol,
sodium chloride or precipitated micronised silica. Examples of solubilizers include, but
are not limited to cetostearyl alcohol, cholesterol, diethanolamine, ethyl oleate, ethylene
glycol palmitostearate, glycerin, glyceryl monostearate, isopropyl myristate, lecithin,
medium-chain glyceride, monoethanolamine, oleic acid, propylene glycol,
polyoxyethylene alkyl ether, polyoxyethylene castor oil glycoside, polyethylene sorbitan
fatty acid ester, polyoxyethylene stearate, propylene glycol alginate, sorbitan fatty acid
ester, stearic acid, sunflower oil, triethanolmine,or combinations thereof. Souring agents
include, but are not limited to, monosodium fumarate and/or citric acid. The compositions
of the present invention may also include stabilizers such as, but not limited to, those
described above under drug-resin complexes.
Suitable viscolizers include, but are not limited to, coprocessed microcrystalline cellulose
such as but not limited to, Avicel RC591, Avicel CL-61 1, D-sorbitol solution, polyalkylene
oxides such as, but not limited to polyethylene oxide; cellulose ethers such as, but not
limited to hydroxyethyl cellulose, hydroxypropylcellulose, hydroxypropyl methyl cellulose,
methyl cellulose, ethyl cellulose, sodium carboxy methylcellulose, calcium carboxymethyl
cellulose, microcrystalline cellulose; gums such as but not limited to gum arabic
alginates, agar, sodium alginate guar gum, locust bean, carrageenan, tara, gum arabic,
tragacanth, pectin, xanthan, gellan, maltodextrin, galactomannan, pusstulan, laminarin,
scleroglucan, gum arabic, inulin, karaya, whelan; polyols such as, but not limited to
dipropylene glycol, polypropylene glycol, propylene glycol, polyethylene glycol (PEG),
sorbitol and glycerol; carbopol, starch and starch-based polymers such as, but not
limited to, pregelatinized starch, acrylic acid and methacrylic acid polymers, and esters
thereof, maleic anhydride polymers; polymaleic acid; poly(acrylamides); poly(olefinic
alcohol)s; poly(N-vinyl lactams); polyoxyethylated saccharides; polyoxazolines;
polyvinylamines; polyvinylacetates; polyimines; povidone, vinylpyrrolidone/vinyl acetate
copolymer and polyvinyl acetate, mixture of polyvinyl acetate and polyvinylpyrrolidone,
chitin, cyclodextrin, gelatin, chitosan and the like or any mixtures thereof.
Suitable surfactants include, but are not limited to, anionic, nonionic, cationic, and
zwitterionic surfactants or a mixture thereof. The non-ionic surfactants employed in the
composition may include, but are not limited to, ethoxylated fatty acid ester, ethoxylated
fatty acid ethers, ethoxylated sorbitan ethers, ethoxylated alkyl-phenols, glycerol esters,
glycerol sugar esters, polyoxyethyleneglycerol monolaurate, polyoxyethyleneglycerol
monostearate, polyoxyethylene-20-cetyl stearate, polyoxyethylene-25-cetyl stearate,
polyoxyethylene (25)-oxypropylene monostearate, polyoxyethylene-20-sorbitan
monopalmitate, poly-oxyethylene-1 6-tert-octylphenol, polyoxyethylene-20-cetyl ether,
polyethylene glycol(1 000) monocetyl ether, ethoxylated castor oil, polyoxyethylene
sorbitol-lanolin derivatives, polyoxyethylene(25)propylene glycol stearate,
polyoxyethylenesorbitol esters, polyoxyethylene-20-sorbitan monopalmitate,
polyoxyethylene-1 6-tert-octylphenol, polyoxyethylene-20-cetyl ether, glycyeryl
undecylenate and Polysorbate 60, capmul (medium chain glyceride) .peceol (glyceryl
monooleate), glyceryl laurate and glyceryl caprylate (Capmul MCM), PEG sorbitan fatty
acid esters like PEG-20 sorbitan monolaurate (Tween 20), PEG-20 sorbitan
monostearate (Tween 60), PEG-20 sorbitan monooleate (Tween 80), sorbitan fatty acid
esters like sorbitan monolaurate (Span 20), glyceryl stearate (Cithrol GMS) or the like
and mixtures thereof. Suitable cationic surfactants include, but are not limited to,
quaternary ammonium compounds, alkylamidoamines and quaternary ester compounds,
distearyl dimethyl ammonium chloride, dimyristyl dimethyl ammonium chloride, dipalmityl
dimethyl ammonium chloride or the like and mixtures thereof. Suitable anionic
surfactants include, but are not limited to, fatty alcohol sulfates, alpha olefin sulfonates,
sulfosuccinates, phosphate esters, carboxylates, sarcosinates, alkyl benzene sulfonates,
alkyl sulfonates, olefin sulfonates, alkyl ethersulfonates, glycerol ethersulfonates, amethyl
estersulfonates, sulfonic fatty acids, alkyl sulfates, fatty alcohol ethersulfates,
glycerol ethersulfates, mixed hydroxy ethersulfates, monoglyceride (ether)sulfates, fatty
acid amide (ether)sulfates, sulfosuccinates, sulfosuccinamates, sulfotriglycerides, amide
soaps, ether carboxylic acids, isethionates, sarcosinates, taurides, alkyl oligoglycoside
sulfates, alkyl (ether)phosphates or the like and mixtures thereof. Suitable zwitterionic
surfactants employed include, but are not limited to, N-alkyl-N,N-dimethyl ammonium
glycinates, for example cocoalkyl dimethyl ammonium glycinate, N-acyl aminopropyl-
N,N-dimethyl ammonium glycinates, cocoacyl aminoethyl hydroxyethyl carboxymethyl
glycinate or the like and mixtures thereof.
Further, the composition of the present invention may further comprise a preservative
such as but not limited to methyl parahydroxybenzoate, propyl parahydroxybenzoate and
sodium benzoate. Suitable cosolvent that may be used includes, but is not limited to,
ethanol and polyhydric alcohols such as, but not limited to, glycerin, propylene glycol,
low molecular weight polyethylene glycols, and mixtures thereof. Further anti-caking
agents that may be optionally incorporated include, but are not limited to, colloidal silicon
dioxide, tribasic calcium phosphate, powdered cellulose, magnesium trisilicate, starch,
and mixtures thereof. Suitable sweetening agent includes, but is not limited to,
aspartame, stevia extract, glycyrrhiza, saccharine, saccharine sodium, acesulfame,
sucralose, dipotassium glycyrrhizinate, galactose, fructose, high fructose corn syrup,
dextrose, sucrose, sugar, maltose, partially hydrolyzed starch, corn syrup solids, sorbitol,
xylitol, mannitol and the like or mixtures thereof. The compositions may comprise one or
more natural and/or artificial flavors such as, but not limited to, mint flavour, orange
flavour, lemon flavors, strawberry aroma, vanilla flavour, raspberry aroma, cherry flavor,
tutty frutty flavor, magnasweet 135, key lime flavor, grape flavor, trusil art 5 11815, and
fruit extracts and the like. Suitable colorants include, but are not limited to, pigments and
dyes such as FD&C Red, FD&C Yellow, FD&C Green, and FD&C Blue and the like or
combinations thereof.
In one of the embodiment, the solid dosage form of the present invention may be
optionally coated. Surface coating may be employed for aesthetic purposes or for
dimensionally stabilizing the compressed dosage form. The coating may be carried out
using any conventional technique employing conventional ingredients suitable for oral
use. A surface coating can, for example, be in the form of a film using conventional
polymers including, but not limited to, hydroxypropyl methyl cellulose, hydroxypropyl
cellulose, carboxymethyl cellulose, polyvinyl alcohol polymethacrylates and the like, and
combinations thereof. In another embodiment of the present invention, the composition
may be optionally coated with a functional coat. The functional coat may be applied
using coating agents including, but not limited to, hydrophilic polymers, hydrophobic
polymers, waxes, and the like, or mixtures thereof, either alone or in combination, along
with plasticizers, colorants, opacifiers etc. The functional coat may help provide the
desired drug release profile.
The sustained release compositions of the present invention can be readily formulated
according to methods well known to those skilled in the art. Method of preparation of the
compositions of the present invention depends on the final dosage form desired.
The compositions of the present invention provide sustained release of the active agent
in-vitro and in-vivo for up to about 24 hours. In one embodiment the compositions of the
present invention provide sustained release of the active agent in-vitro and in-vivo for up
to about 12 hours. In another embodiment the compositions of the present invention
provide sustained release of the anti-tussive agent in-vitro and in-vivo for up to about 2
hours. In another embodiment, the compositions of the present invention provide
sustained release of the anti-tussive agent in-vitro and in-vivo for about 6 to about 12
hours. In yet another embodiment, the compositions of the present invention provide
sustained release of the anti-tussive agent in-vitro and in-vivo for up to about 24 hours.
In still another embodiment, the compositions of the present invention provide sustained
release of the anti-tussive agent in-vitro and in-vivo for about 6 to about 24 hours.
In a further embodiment is provided use of the sustained release compositions of the
present invention for the prevention, treatment, management or mitigation of various
disease conditions or disorders depending on the active agent employed. In one
embodiment is provided use of the sustained release compositions of the present
invention for the treatment, management or mitigation of cough, cold, cold-like and/or flu
symptoms and the discomfort, pain, headache, fever and general malaise associated
therewith. In another embodiment is provided use of the sustained release compositions
of the present invention for the manufacture of a medicament for the prevention,
treatment, management or mitigation of various disease conditions or disorders
depending on the active agent employed. In a still further embodiment is provided use of
the sustained release compositions of the present invention for the manufacture of a
medicament for the treatment, management or mitigation of cough, cold, cold-like and/or
flu symptoms and the discomfort, pain, headache, fever and general malaise associated
therewith. In another embodiment, a method of treating, managing or mitigating cough,
cold, cold-like and/or flu symptoms and the discomfort, pain, headache, fever and
general malaise associated therewith is provided which comprises administering to the
subject in need thereof sustained release composition of the present invention.
In another embodiment, the invention also relates to sustained release compositions
comprising at least one second or additional active agent in addition to at least one
active agent present in the compositions. In one embodiment, the second or additional
active agent is for immediate release. In another embodiment, the second or additional
active agent is different than the first active agent that is delivered in a sustained
manner. In still another embodiment the second or additional active agent is complexed
with ion-exchange resin. In another embodiment the second active agent is not
complexed with ion exchange resin. In a further embodiment the second active agent or
additional active agent is delivered in a sustained release manner. Such a second or
additional active agent includes, but is not limited to, the list of active agents discussed
above under active agents.
While the invention has been described with reference to exemplary embodiments, it will
be understood by those skilled in the art that various changes may be made and
equivalents may be substituted for elements thereof without departing from the scope of
the invention. In addition, many modifications may be made to adapt a particular
situation or material to the teachings without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the particular embodiment
disclosed, but that the invention will include all embodiments falling within the scope
thereof. Details of the present invention, including its objects and advantages, are
provided in the non-limiting exemplary illustrations below.
EXAMPLES
Example 1 : Comparative evaluation of drug release from sustained release
dextromethorphan compositions
Comparative evaluation of three sustained release dextromethorphan compositions was
carried out. The three compositions being evaluated comprised:
A) Coated drug-resin complexes; wherein all the drug-resin complexes are coated at
a single coating level of 25% by weight of the drug-resin complex.
B) Coated drug-resin complexes of A and uncoated drug-resin complexes in a ratio
of 2:1.
C) Coated drug resin complexes of the present invention that are variably coated
and as per an embodiment a portion of drug-resin complexes are coated at one
coating level of 5% by weight of the drug-resin complex while another portion of
drug-resin complexes are coated at another coating level of 25% by weight of the
drug-resin complex and present in a ratio of 1:2 respectively.
Table 1: Compositions of dextromethorphan sustained release beads
Procedure: Dextromethorphan HBr was complexed using ion exchange resin in water
under stirring. The drug-resin complex formed was filtered, dried and solvated. This
treated drug-resin complex was then coated with ethyl cellulose to a coating level of 5%
weight gain and 25 % weight gain. A separate portion of drug-resin complex was not
coated with ethyl cellulose. These beads were then incorporated into the following
suspension base.
Table 2: Composition of suspension base
Procedure: Methylparaben, propylparaben, disodium EDTA were dissolved in purified
water at 85-90°C. Pharma grade sugar was added to above solution under stirring and
solution was subsequently cooled to room temperature. Xanthan gum was dispersed in
high fructose corn syrup under stirring. This dispersion was added to the above sugar
syrup under stirring to get uniform dispersion. Solution of color and flavor was then
added. The beads were then added to the syrup base along with polyoxyethylene
sorbitan fatty acid esters and citric acid. Final volume was adjusted with purified water.
For composition "A" only 25% coated drug-resin complexes were added in suspension
base. For composition "B" combination of 25% coated and uncoated drug-resin
complexes in ratio of 2:1 respectively were added in suspension base. For composition
"C" combination of 5% coated drug-resin complexes and 25% coated drug-resin
complexes in a proportion of 1:2 respectively were added in suspension base.
Comparative dissolution profile of the three compositions was evaluated in pH change
media using USP Type I I apparatus and 100 rpm speed. The pH change media to be
used was 0.1N HCI for 1 hour followed by pH 6.6 phosphate buffer.
Table 3: Comparative dissolution profiles of the three compositions
The comparative study of the three compositions shows that composition "A" shows
excessive retardation of drug release while composition "B" shows faster drug release
and Composition "C" shows optimal release profile of the drug from the composition that
is neither too retarded nor too fast.
Example 2 : Dextromethorphan sustained release suspensions
Table 4: Composition of dextromethorphan sustained release suspension
Ingredients mg/5ml
Dextromethorphan HBr 30
Sodium polystyrene sulfonate, USP 60
Polyethylene glycol, USPNF 32
Sodium metabisulphite, USPNF 20
Ethyl cellulose, USP 2 1.81
Dibutyl sebacate, USPNF 6.51
Isopropyl alcohol 293.25
Pharma grade sugar 1750
Methylparaben, USPNF 5
Propylparaben, USPNF 0.5
High fructose corn syrup 850
Xanthan gum, USPNF 5.5
Orange flavor 9
FD & C Yellow 0.375
FD & C Red 0.375
Polyoxyethylene sorbitan fatty acid 5
esters, USP
Citric acid anhydrous, USP 7.5
Purified water qs 100
Same procedure as for example 1(C) was employed for the preparation of the sustained
release preparation.
This dextromethorphan suspension has a desired sustained release profile.
Example 3 : Dextromethorphan sustained release suspensions
Table 5 : Composition of dextromethorphan sustained release suspension
Same procedure as for Example 1(C) is employed for the preparation of the sustained
release preparation
This dextromethorphan suspension has a desired sustained release profile.
Example 4 : Dextromethorphan sustained release orally disintegrating tablets
Table 6: Composition of dextromethorphan sustained release
orally disintegrating tablets
Procedure: Sodium metabisulphite, dextromethorphan HBr and Amberlite IRP 69 were
added to water under stirring. The drug-resin complex formed was filtered, dried and
solvated. This treated drug-resin complex was then coated with ethyl cellulose to a
coating level of 5% weight gain and 25 % weight gain. The coated drug-resin complexes
were blended with other excipients, lubricated and the lubricated blend was compressed
to form orally disintegrating tablets with the following parameters:
Hardness (N) 30-40
Friability (%) 0.40
Disintegration time (sec) 15-20
Disintegration time in oral cavity (sec) 40-50
Tablets with desired taste-masking, friability and disintegration time were obtained.
CLAIMS
We claim:
1) A sustained release composition comprising plurality of sustained release beads
comprising coated drug-resin complexes comprising:
a . drug-resin complex; and
b. release modifier coating.
2) The composition of claim 1 wherein the drug-resin complex comprises at least one
active agent and at least one ion-exchange resin.
The composition of claim 2 wherein the active agent is an anti-tussive agent, an
analgesic, an antihistamine, an expectorant, a mucolytic, a decongestant, an
analeptic agent, an anesthetic agent, an anti-asthmatic, an anti-arthritic agent; an
anti-cancer agent, an anti-cholinergic agent, an anti-convulsant agent, an ant i
depressant agent, an antidiabetic, an anti-helminthic agent, an anti-diarrheal agent;
an anti-epileptic, an anti-hyperlipidemic agent; an antihypertensive, an
antihypotensive, an anti-infective agent, an anti-inflammatory agent, a non-steroidal
anti-inflammatory agent, an anti-emetic, an anti-migraine agent; an anti-neoplastic
agent, an anti-tubercular agent, an antibiotic, an antacid, an antiulcer agent; an anti-
Parkinsonism drug, an anti-pruritic agent, an antipsychotic agent, an anti-pyretic
agent, an anti-spasmodic, an anti-viral agent, an anxiolytic agent, an appetite
suppressant, an attention deficit hyperactivity disorder treating agent, a
cardiovascular agent, a calcium channel blocker, an antianginal agent, a central
nervous system agent, a beta-blocker, an antiarrhythmic agent, a bronchodilator, a
central nervous system stimulant, a diuretic, a genetic material, a hormoholytic, a
hypnotic, a hypercalcemia a hypoglycemic agent, an immunosuppressive agent, an
antimuscarinic, a genitourinary smooth muscle relaxant, a beta-agonist, a narcotic
antagonist, nicotine, a nutritional agent, a parasympatholytic, a peptide drug, an
antihemorrhoidal, a psychostimulant, a psychotropic, a mucolytic, a sedative, a
laxative, a vitamin, a sialagogue, a steroid, a sympathomimetic, a tranquilizer, or a
vasodilator or a combination thereof in the form of free base, free acid,
pharmaceutically acceptable salt, prodrug, active metabolite, polymorph, solvate,
hydrate, enantiomer, optical isomer, tautomer or racemic mixture thereof.
4) The composition of claim 2 wherein the active agent is dextromethorphan,
hydrocodone, chlorpheniramine, phenylephrine, pseudoephedrine, codeine,
morphine, dihydromorphone, oxycodone, dimenhydrinate, diphenhydramine,
brompheniramine, cetirizine, levocetirizine, ambroxol, bromhexine, carbocisteine,
domiodol, guaifenesin, hydroxyzine, dexbrompheniramine, fexofenadine, terfenadine,
dexchlorpheniramine or combination thereof in the form of free base, free acid,
pharmaceutically acceptable salt, prodrug, active metabolite, polymorph, solvate,
_hydrate, enantiomer, optical isomer, tautomer or racemic mixture thereof.
5) The composition of claim 2 wherein the ion exchange resin is a cation exchange
resin or an anion exchange resin or combination thereof.
6) The composition of claim 2 wherein the cation exchange resin is a copolymer of
methacrylic acid and divinylbenzene, a sodium polystyrene sulfonate resin, a
sulfonated copolymer of styrene and divinylbenzene, a crosslinked polyacrylic acid
resin, a polyacrylate resin, a crosslinked carboxylic acid resin, a crosslinked sulfonic
acid resin, a crosslinked phosphonic acid resin, zeolite or a combination thereof.
7) The composition of claim 2 wherein the active agent and the ion exchange resin are
present in a ratio of about 1:0.1 to about 1:20 in the drug-resin complex.
8) The composition of claim 1 wherein the release modifier coating comprises at least
one release modifier, said release modifier being a water-insoluble release modifier,
a water-soluble release modifier or a combination thereof.
9) The composition of claim 8 wherein the water-insoluble release modifier is a
polymeric water-insoluble release modifier, a non-polymeric water-insoluble release
modifier or a combination thereof.
10) The composition of claim 9 wherein the polymeric water-insoluble release modifier is
polyvinyl acetate, polyvinyl chloride, polyvinyl carbonate, ethyl cellulose,
nitrocellulose, vinylidene chloride-acrylonitrile copolymer, acrylonitrile-styrene
copolymer, ethylene vinyl acetate, cellulose acetate, cellulose acetate phthalate,
cellulose acetate butyrate, copolymer of vinyl pyrrolidone,
hydroxypropylmethylcellulose phthalate, methacrylic acid copolymer, or methacrylate
copolymer or a combination thereof.
11) The composition of claim 8 wherein the water-soluble release modifier is
polyvinylpyrrolidone, poloxamer, guar gum, xanthan gum, gum arabic, tragacanthan,
cellulose derivatives such as hydroxypropylmethylcellulose, hydroxypropyl cellulose,
methylcellulose, and hydroxyethyl cellulose, carboxymethylethyl cellulose,
hydroxyethyImethyl carboxymethyl cellulose, hydroxyethyl methyl cellulose,
carboxymethyl cellulose, methylhydroxyethyl cellulose, or methylhydroxypropyl
cellulose or a combination thereof.
12) The composition of claim 1 wherein the coated drug-resin complexes are present in
the form of at least two populations of variably coated drug-resin complexes.
13) The composition of claim 12 wherein the variably coated drug-resin complexes
comprise at least one population of drug-resin complexes coated with at least one
release modifier from about 1% to about 25% by weight of the drug-resin complex;
and at least one population of drug-resin complexes coated with at least one release
modifier from about 5% to about 75% by weight of the drug-resin complex.
14) The composition of claim 12 wherein the variably coated drug-resin complexes
comprise at least one population of drug-resin complexes coated with at least one
release modifier from about 1% to about 15% by weight of the drug-resin complex;
and at least one population of drug-resin complexes coated with at least one release
modifier from about 15% to about 75% by weight of the drug-resin complex.
15) The composition of claim 1 wherein the sustained release composition comprising
plurality of sustained release beads comprising coated drug-resin complexes
comprising:
a. drug-resin complex comprising at least one active agent and at least one ionexchange
resin; and
b. release modifier coating;
wherein coated drug-resin complexes are present in the form of at least two
populations of variably coated drug-resin complexes comprising at least one
population of drug-resin complexes coated with at least one release modifier from
about 1% to about 25% by weight of the drug-resin complex; and at least one
population of drug-resin complexes coated with at least one release modifier from
about 5% to about 75% by weight of the drug-resin complex.
16) The composition of claim 1 wherein the sustained release beads further comprise at
least one pharmaceutically acceptable excipient, said pharmaceutically acceptable
excipient being a diluent, a stabilizer, or a release modifier or mixture thereof.
17) The composition of claim 1 wherein the sustained release composition is in the form
of a liquid, a solid or a semisolid preparation; said liquid preparation being
suspension and said solid preparation being capsule, tablet, caplet, orally
disintegrating tablet, dispersible tablet, dry suspension for reconstitution, granule,
wafer or bite-dispersion tablet.
18) The composition of claim 1 wherein the sustained release composition further
comprises at least one pharmaceutically acceptable excipient; said pharmaceutically
acceptable excipient being binder, disintegrant, superdisintegrant, diluent, salivating
agent, surfactant, flavor, sweetener, colorant, souring agent, viscolizer, glidant,
lubricant, solubilizer, stabilizer, suspending agent, preservative, cosolvent, anticaking
agent, or buffer or a combination thereof.
19) The composition of claim 1 wherein the sustained release composition further
comprises an additional active agent.
20) The composition of claim 19 wherein the additional active agent is delivered in an
immediate release or sustained release manner.