DESC:FORM 2
THE PATENTS ACT 1970
(39 of 1970)
AND
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule13)
1. TITLE OF THE INVENTION:

“INTRANASAL PHARMACEUTICAL COMPOSITIONS OF POLYMERIC NANOPARTICLES”

2. APPLICANT:

(a) NAME: CIPLA LIMITED

(b)NATIONALITY: Indian Company incorporated under the
Companies Act, 1956

(c) ADDRESS: Mumbai Central, Mumbai – 400 008, Maharashtra, India.

3. PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the invention and the manner in which it is to be formed.

FIELD OF THE INVENTON:
The present invention relates to intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs, a process for preparing such intranasal pharmaceutical compositions and their use in the treatment of tumours, especially brain tumours.

BACKGROUND AND PRIOR ART:
Malignant brain tumours are comprised of a number of malignancies including gliomas, medulloblastomas, primary central nervous system lymphomas and brain metastases. Most brain tumours are gliomas which originate in the glial cells. Gliomas can be described as low grade which have slow growth, intermediate grade which are more aggressive and high grade which are the most aggressive.

Astrocytoma is the most common type of glioma which usually originates from astrocytes that are located in the cerebrum and cerebellum. Glioblastoma multiforme is a form of very aggressive astrocytoma.

Glioblastomamultiforme (GBM) are the most common form of primary brain tumours occurring at an incidence rate of 14 cases per 1,00,000 adults in United States of America. Glioblastomamultiforme is the most dangerous type of brain tumour that remains poorly prognosed despite the progress in chemotherapy and radiation.

Currently, the treatment of Glioblastomamultiforme is carried out by administering oral alkylating agents and nitrosoureas, especially by administration of temozolomide and bevacizumab.

Further, surgical resection, concomitant administration of chemotherapy and radiation, use of heavy particle radiations, intracerebral and intraventricular injections of anticancer agents, convection enhanced delivery involving the administration of the chemotherapeutic agent by causing disruption of the BBB are some of the other approaches for treating brain tumours.

However, despite various advances in understanding the molecular biogenesis and makeup of the brain, treatment of the brain tumour remains dismal.

One of the major reasons for failure of chemotherapy in the treatment of brain tumours is the presence of the Blood Brain Barrier (BBB). The Blood Brain Barrier is composed of tight junctions formed due to the embracing of endothelial cells, pericytes and astrocytes together. These tight junctions allow the passage of few small sized particles, hydrophobic materials (only 2%) and agents that are required by the cells for their growth.

Further, factors like auto-protective nature of the brain (BBB and alignment of brain cells), genomic alterations occurring in tumour cells, efflux transporters on the barrier and properties of chemical agents used for treatment of brain tumours cause difficulty in the delivery of anticancer agents to the brain.

The anatomy of the tumour, resistance of the cells to apoptosis, cytotoxic drugs and radiotherapy makes the treatment of tumours extremely difficult.

Hence, the approaches for the better treatment of brain tumours include pharmacological approach and physiological approach. Physiological based approach involves disruption of BBB using osmotic agents and convection enhanced delivery (CED), whereas pharmacological approach includes modification of chemical structure of the drug by synthesizing a prodrug.

However; such approaches are disadvantageous as they may cause infections and the intrusion of foreign matter into the brain. Further, the anticancer drug may get cleared before it even reaches the cancer cells.

Hence, to overcome the in vivo barrier, the pharmaceutical approach can be employed which focusses on bypassing the BBB by using a novel, practical, simple and non-invasive approach namely intranasal delivery. The neural connections between the nasal mucosa and the brain provide a unique pathway for the non-invasive delivery of therapeutic agents to the CNS. This pathway also allows drugs which do not cross the BBB to enter the CNS and it eliminates the need for systemic delivery and thereby reducing unwanted systemic side effects.

Further, one of the characteristics that distinguish anticancer agents from other drugs is the frequency and severity of side effects at therapeutic doses. These side effects may be acute or chronic, self-limited, permanent, mild or potentially life threatening. Hence management of these side effects is of utmost importance because they affect the treatment, tolerability and overall quality of life. Common toxicities that may be encountered are haematological, gastrointestinal, skin and hair follicle toxicity, nervous system toxicity, local toxicity, metabolic abnormalities, hepatic toxicity, urinary tract toxicity, cardiac toxicity, pulmonary toxicity, gonadal toxicity etc.

Measures that can ameliorate the toxicities of anticancer drugs, include dose reduction, use of alternate drugs or their analogues, growth factors, and cytoprotective agents. However, employing any of these measures might affect the treatment and ultimately the therapeutic efficacy of the desired anticancer agent/s.

Further, anticancer drugs cannot greatly differentiate between cancerous and normal cells, leading to systemic toxicity and adverse effects. In addition, rapid elimination and widespread distribution into non targeted organs and tissues require the administration of the anticancer drug in large doses, which may not be economical as well as may exhibit nonspecific toxicity to such non targeted organs.

Nanoparticles of anticancer agents exhibit several advantages in the delivery of such agents by virtue of their small average particle size. Such nanoparticles are hydrophobic in nature and can cross the BBB to some extent.

Use of nanoparticles for cerebral cancer. Tumori 94, 271-277, Kreuter, J., Gelperina, S., 2008.

Influence of particle size on transport of methotrexate across blood brain barrier by polysorbate 80-coated polybutylcyanoacrylate nanoparticles. Int J Pharm 310, 213-219, Gao, K., Jiang, X., 2006.
Drug transport to brain with targeted nanoparticles. NeuroRx 2, 108-119, Olivier, J.C., 2005

Enhanced brain targeting of temozolomide in polysorbate-80 coated polybutylcyanoacrylate, nanoparticles, Xin-Hua Tian et al, International Journal of Nanomedicine 2011:6 445–452.

Composite Polylactic-Methacrylic Acid Copolymer Nanoparticles for the Delivery of Methotrexate, BonganiSibeko et al, Journal of Drug Delivery, Volume 2012 (2012), Article ID 579629, 18 pages. However, PLA-MAA nanoparticles of methotrexate prepared by double emulsion solvent evaporation technique as disclosed in this article are unstable and not homogenous which may ultimately affect the delivery of the anticancer drug to the site of action.

Furthermore, the use of nanoparticles comprising anti-cancer agents in prior art is only discussed in the context of aiding the passage of the anti-cancer agents across the blood brain barrier with the nanoparticles.

Intranasal delivery: An approach to bypass the blood brain barrier, Indian Journal of Pharmacology, Talegaonkar S, Vol. 36, No. 3, June, 2004, pp. 140-147.

New strategies to deliver anticancer drugs to brain tumours, Valentino Laquintana et al, Expert Opinion Drug Delivery. 2009 October; 6(10): 1017–1032.

New therapeutic approach for brain tumors: Intranasal delivery of telomerase inhibitor GRN163, RintaroHashizume et al, Neuro-Oncology, April 2008.

However, the major problems associated with the nasal delivery of anticancer drugs is the low residence time, high mucociliary clearance and rapid metabolism in the highly active enzymatic region of the nasal mucosa.

Further, the difficulties while formulating nasal compositions include an enzymatically active and low pH nasal epithelium, mucosal irritation and patient to patient variability caused by nasal pathology.

Although intranasal delivery of anticancer drugs is known the prior art reports that such delivery may not be target oriented for most anticancer drugs. Specifically anticancer drugs such as methotrexate, 5-FU and raltitrexed which have been delivered using intranasal delivery failed to discriminate between tumour tissues and normal tissues thus leading to the toxicity of normal neural tissues. Further, the concentrations of such anticancer drug solutions in the brain are low due to minimised residence time of such intranasal formulations.

The inventors of the present invention have acknowledged the aforementioned drawbacks associated with known intranasal compositions comprising anti-cancer drugs, and have sought ways of addressing them. The inventors have appreciated that it would be useful to provide an intranasal pharmaceutical composition of anticancer drugs that exhibits immediate or prolonged release, has an increased residence time in the nasal mucosa, is mucoadhesive, and specifically targets the brain tumour cells over healthy cells.

OBJECT OF THE INVENTION:
An object of the present invention is to provide intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs.

Another object of the present invention is to provide intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs exhibiting immediate or prolonged release.

Another object of the present invention is to provide intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs with increased residence time in the nasal cavity specifically targeting the brain tumour cells.

Another object of the present invention is to provide intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs which are mucoadhesive.

Another object of the present invention is to provide intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs having improved surface area and solubility.

Another object of the present invention is to provide intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs requiring a reduced dose of anti-cancer drug in the pharmaceutical composition.

Another object of the present invention is to provide intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs having reduced side effects.

Another object of the present invention is to provide intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs that effectively bypass the Blood Brain Barrier.

Another object of the present invention is to provide the use in the treatment of brain tumours by administering intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs exhibiting increased residence time in the nasal cavity and improved targeting of brain tumour cells.

SUMMARY OF THE INVENTION:
According to an aspect of the present invention, there is provided an intranasal pharmaceutical composition comprising one or more polymeric nanoparticles of one or more anti-cancer drugs and optionally one or more pharmaceutically acceptable excipients.
Preferably, the one or more anti-cancer drugs comprise methotrexate. Preferably, the one or more polymeric nanoparticles comprises polylactic acid (PLA), polylacticglycolic acid (PLGA), or any combination thereof.
According to another aspect of the invention, there is provided a process for the preparation of intranasal pharmaceutical composition of the invention, wherein the process comprises formulating one or more polymeric nanoparticles comprising one or more anti-cancer agents with one or more pharmaceutically acceptable excipients to provide the intranasal pharmaceutical composition.

Preferably, the process comprises encapsulating one or more anti-cancer agents within a polymer to provide one or more polymeric nanoparticles comprising the one or more anti-cancer agents. More preferably, the process comprises solvent evaporation.

According to another aspect of the invention, there is provided an intranasal pharmaceutical composition of the invention for use in the treatment of brain tumours. Preferably, the brain tumours comprise glioblastomamultiforme (GBM) or anaplastic astrocytomas (AA). According to another aspect of the invention, there is provided the use of intranasal pharmaceutical compositions of the invention in the manufacture of a medicament for treating brain tumours. Preferably, the brain tumours comprise glioblastomamultiforme (GBM) or anaplastic astrocytomas (AA).

According to an aspect of the invention, there is provided a method of treating brain tumours wherein the method comprises administering intranasal pharmaceutical compositions of the invention to a patient in need thereof. Preferably, the brain tumours comprise glioblastomamultiforme (GBM) or anaplastic astrocytomas (AA).

BRIEF DESCRIPTION OF THE DRAWINGS:
Figure 1: In vitro release of methotrexate (MTX) and nasal methotrexate nanoparticles (MTX-NP).
The pure MTX demonstrated a 100% release from the dialysis bag in just less than two hours as compared to the, MTX-NP which continued to release MTX for more than 72 hours. 50% of the trapped MTX was released in~16 hours followed by the release of the remaining trapped MTX.
Figure 2: Pharmacokinetic study of methotrexate (MTX) and nasal methotrexate nanoparticles (MTX-NP).
The pure MTX rapidly disappeared from the circulation due to its short half-life. MTX-NP enhanced the maximum drug concentration (Cmax) and the area under the concentration–time curve (AUC) 1.5 times as compared with pure MTX solution administered via the intranasal route. (p<0.01).
Figure 3: Brain Deposition studies of methotrexate (MTX) and nasal methotrexate nanoparticles (MTX-NP)
The drug concentration of the intranasally administered MTX- NP achieved in the brain is four times higher as compared to intransally administered pure MTX at 24 hours thus demonstrating the ability of nanoparticles to deliver the drug to the brain.
The results obtained for lung tissue deposition indicates that intranasally administered pure drug gets distributed in the lungs following the trachea- bronchial deposition. The amount of drug deposited in the lung was significantly lowered when the drug was administered in the form of mucoadhesive nanoparticles due to increased residence of the nanoparticles in nasal cavity.
Figure 4: Cytotoxicity assay of methotrexate (MTX), nasal methotrexate nanoparticles (MTX_NP) and plain nanoparticles (P-NP)
After 24 hours sufficient MTX is released to mediate cytotoxic effect and this effect increases with incubation time. P-NP compositions prepared similarly exhibited no cytoxicity at the tested concentrations.

DETAILED DESCRIPTION OF THE INVENTION:
Intranasal delivery provides a practical, non-invasive method for delivering anticancer drugs to the brain because of the unique anatomic connections provided by the olfactory and trigeminal nerves. Intranasally administered anticancer drugs can reach the brain parenchyma, spinal cord, and cerebrospinal fluid (CSF) within minutes by using an extracellular route through perineural and/or perivascular channels along the olfactory and trigeminal nerves without binding to any receptor.

These agents can also be transported into the brain following the axonal transport. The intranasal delivery not only bypasses the BBB, but also provides rapid delivery of the anticancer drugs to the CNS, avoids hepatic first-pass drug metabolism, reduces unwanted systemic side effects and eliminates the need for systemic delivery of such anticancer drugs.
Further, intranasal delivery is very convenient as patients can self-administer such compositions enhancing patient compliance, the only limitation being that the nasal cavity is cleared at regular intervals (approximately after every 20 minutes) by the mucociliary clearance mechanism which may lead to the loss of anticancer drug
However, polymeric nanoparticles protect the anticancer drugs from degradation in nasal enzymatic milieu and provide better absorption through the nasal membrane. Nanoparticles by virtue of their small size demonstrate numerous advantages. Further, the loss of anticancer drugs from the nanoparticles by mucociliary movement of the nasal cavity can be prevented by fabricating the mucoadhesive particles.

Accordingly, the fabricated nanoparticles comprising the anticancer drugs are preferably formulated in a thermosensitive base that gels upon administration into the nasal cavity, adheres to the nasal mucosa, thus increasing residence time of the drug in the nasal cavity.
The intranasal pharmaceutical compositions comprising a thermosensitive base are preferably dropped or sprayed as fine droplets into the nasal cavity and spread over a larger surface area on the nasal mucosa in solution state. After being administered into nasal cavity, the solution transforms into a viscous hydrogel at body temperature, which ultimately decreases the nasal mucociliary clearance rate by adhering to the nasal mucosal membrane increasing the residence time of the drug in the nasal mucosa. This behaviour is due to the presence of the thermosensitive base, which is not used in previously known intranasal compositions comprising anticancer drugs. The formation of the viscous hydrogel also provides immediate or prolonged release of the drug.

Further, such intranasal pharmaceutical compositions are stable, exhibits reduced side effects as well as decreases the number of applications to the nasal cavity ultimately leading to improved patient compliance.

Biodegradable polymeric nanoparticulate drug delivery systems have the ability to target therapeutic drugs to the site of action as well as reduce the toxicity or side effects and are preferred due to their non-toxic as well as non-immunogenic nature, enabling them to act as potential carriers.
Such nanoparticulate based polymeric drug delivery system are advantageous due to adjustable properties such as biodegradability, good biocompatibility and amphiphilic characteristics, controlled release, targeted delivery and therapeutic impact.

The polymeric biodegradable materials used in such nanoparticulate drug delivery system are natural or synthetic in origin and are degraded in vivo, either enzymatically or non-enzymatically or both, to produce biocompatible, toxicologically safe by-products which are further eliminated by the normal metabolic pathways.

The basic category of biomaterials used in drug delivery can be broadly classified as synthetic biodegradable polymers, semi-synthetic and natural, such as, but not limited to, the
-hydroxy acids such aspolylactic acid and polylacticcoglycolic acid;, polyanhydrides; naturally occurring polymers such as complex sugars such as hyaluronan and chitosan; inorganics such as hydroxyapatit); polycaprylactones, polymalic acids, polybutylcyanoacrylates, sugars, dextrans, human serum albumin,bovine serum albumin, cellulose derivatives such as hydroxypropylcellulose, hydroxymethylcellulose, hydroxypropylmethylcellulose, methylcellulose polymers hydroxyethylcellulose, sodium carboxymethylcellulose, carboxymethylene and carboxymethylhydroxyethylcellulose; acrylics like acrylic acid, acrylamide, and maleic anhydride polymers, acacia, gum tragacanth, locust bean gum, guar gum, or karaya gum, agar, pectin, carrageenan, gelatin, casein, zein and alginates, polyvinyl alcohol, carboxypolymethylene, bentonite, magnesium aluminum silicate, polysaccharides, modified starch derivatives and copolymers or mixtures thereof. Any of the polymers discussed above can be used to form the polymeric nanoparticles present in the compositions of the invention.

Preferably, the polymers may be present in an amount ranging from about 0.1% to about 35% by weight of the composition.

Polylactic acid (PLA) and polylacticcoglycolicacid (PLGA) have been widely used to synthesize polymeric nanoparticles due to their biodegradability, non-immunogenic, non-toxic and biocompatibility properties.
PLA it is a polymer designed form lactic acid monomer which has its own mechanism of degradation within the body. The hydrophobic nature of the polymer is further suitable for transit of the nanoparticles through the fencing system of the brain.

PLGA is most widely used because of its long clinical experience, favourable degradation characteristics and possibilities for sustained drug delivery. Further, degradation of PLGA can be employed for obtaining sustained release of drugs at desirable doses by implantation without surgical procedures. Additionally, it is possible to alter the physical properties of the polymer-drug matrix by controlling the relevant parameters such as polymer molecular weight, ratio of lactide to glycolide and drug concentration to achieve a desired dosage and release interval depending upon the drug type.

Preferably, PLA and PLGA are the polymers that are employed in forming polymeric nanoparticles for use in the intranasal pharmaceutical compositions of the invention.

Preferably, the intranasal pharmaceutical compositions, according to the present invention, comprises PLA and PLGA nanoparticles of anticancer drugs.

The intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs are preferably engineered to have an affinity for target tissues through passive or active targeting mechanisms.

The intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs preferably exhibits reduced side effects compared with known pharmaceutical compositions comprising anti-cancer drugs.

The intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs preferably demonstrate lesser side effects due to higher amount of drug deposition in the brain owing to high residence time and low mucociliary clearance as compared to the amount of drug deposition in the lung.

The intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs can exhibit immediate or prolonged release.
The intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs of the invention are preferably mucoadhesive.

Mucoadhesiveness increases the residence time of the intranasal pharmaceutical compositions by lowering the mucociliary clearance and also by inhibiting the ciliary movement.

The intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs of the invention also exhibits enhanced BBB passage.

The intranasal pharmaceutical compositions comprising polymeric nanoparticles of anticancer drugs of the invention may preferably have a reduced dose compared with known pharmaceutical compositions in the art comprising anti-cancer drugs.

Anticancer drugs that may be used in the pharmaceutical compositions of the invention may comprise but are not limited to, alkylating agents, anti-metabolites, anti-microtubule agents, topoisomerase inhibitors or antitumor antibiotics, DNA linking agents, biological agents and bisphosphonates, or any combination thereof.

Suitable alkylating agents, that may be used comprise, one or more of, but not limited to, nitrogen mustards, nitrosoureas, tetrazines, aziridines, and non-classical alkylating agents. Nitrogen mustards include mechlorethamine, cyclophosphamide, melphalan, chlorambucil, ifosfamide, busulfan. Nitrosoureas include N-Nitroso-N-methylurea, carmustine, lomustine, semustine, fotemustine, streptozotocin, dacarbazine,bendamustine, procarbazine, mitozolomide, temozolomide, thiotepa, mytomycin, diaziquone and the like or combinations thereof.

Suitable anti-metabolites, that may be used comprise, one or more of, but not limited to, methotrexate, pemetrexed, raltitrexed, asparaginase, fluorouracil, capecitabine, cytarabine, gemcitabine, decitabine, vidaza, fludarabine, nelarabine, cladribine, clofarabine, pentostatin, thioguanine, mercaptopurine and the like or combinations thereof.
Suitable anti-microtubule agents, that may be used comprise, one or more, but not limited to vincristine, vinblastine, paclitaxel, docetaxel, etoposide, irinotecan, topotecan, vinorelbine and the like or combinations thereof.

Suitable topoisomerase inhibitors or antitumor antibiotics, that may be used comprise, one or more, but are not limited to actinomycin D, bleomycin, plicamycin, mitomycin, doxorubicin, daunorubicin, epirubicin, idarubicin, pirarubicin, aclarubicin, mitoxantrone, actinomycin, bleomycin and the like or combinations thereof.

Suitable DNA linking agents, that may be used comprise, one or more, but are not limited to, cisplatin, oxaliplatin, carboplatin and the like or combinations thereof.

Suitable biological agents, that may be used comprise, one or more, but are not limited to, alemtuzamab, BCG, bevacizumab, cetuximab, denosumab, erlotinib, gefitinib, imatinib, interferon, ipilimumab, lapatinib, panitumumab, rituximab, sunitinib, sorafenib, emsirolimus, trastuzumab and the like or combinations thereof.

Suitable bisphosphonates, that may be used comprise, one or more, but are not limited to, clodronate, ibandronic acid, pamidronate, zolendronic acid and the like or combinations thereof.

Suitable other anticancer drugs that may be used comprise, one or more, but are not limited to, anastrozole, abiraterone, amifostine, bexarotene, bicalutamide, buserelin, cyproterone, degarelix, exemestane, flutamide, folinic acid, fulvestrant, goserelin, lanreotide, lenalidomide, letrozole, leuprorelin, medroxyprogesterone, megestrol, mesna, octreotide, stilboestrol, tamoxifen, thalidomide, tiptorelin and the like or combinations thereof.

Preferably, in pharmaceutical compositions of the invention, the one or more anti-cancer drugs comprise an anti-metabolite. Preferably, the antimetabolite comprises methotrexate.
Most preferably, the intranasal pharmaceutical composition, according to the present invention, comprises either PLA or PLGA nanoparticles of methotrexate. Combinations of PLA and PLGA may also be used to form the polymeric nanoparticle comprising the methotrexate.
The term “methotrexate” is used in broad sense to include not only “methotrexate” per se but also its pharmaceutically acceptable derivatives thereof. Suitable derivatives include pharmaceutically acceptable salts, pharmaceutically acceptable solvates, pharmaceutically acceptable hydrates, pharmaceutically acceptable isomers, pharmaceutically acceptable esters, pharmaceutically acceptable anhydrates, pharmaceutically acceptable enantiomers, pharmaceutically acceptable polymorphs, pharmaceutically acceptable prodrugs, pharmaceutically acceptable tautomers and/or pharmaceutically acceptable complexes thereof.

Preferably, the methotrexate may be present in an amount ranging from about 0.1% to about 20% by weight of the composition.

Currently, methotrexate is indicated in the treatment of neoplastic diseases, psoriasis and Rheumatoid Arthritis including Polyarticular-Course Juvenile Rheumatoid Arthritis.

Specifically, methotrexate is employed for treating neoplastic diseases such as gestational choriocarcinoma, chorioadenomadestruens and hydatidiform mole. In acute lymphocytic leukemia, methotrexate is indicated in the prophylaxis of meningeal leukemia.

However, the inventors of the present invention have developed intranasal pharmaceutical compositions comprising PLA as well as PLGA nanoparticles of methotrexate especially for the treatment of Glioblastomamultiforme (GBM) and anaplastic astrocytomas (AA), wherein the intranasal pharmaceutical composition exhibits targeted delivery of methotrexate to the tumour cells and thereby eliminating the delivery of methotrexate to non-targeted organs.

The term "intranasal pharmaceutical composition" is used to refer to nasal dosage forms, such as but not limited to, powders, powder for reconstitution, snuffs, sprays, solutions, suspensions, ointments, drops, in-situ gel, aerosols, ointments, microspheres, creams, gels, patches, films and the like.

Suitable solvents for reconstitution include, but are not limited to, water, purified water for injection, sterile saline solution, dextrose solution, Ringers solution and the like.
The inventors of the present invention have further observed that the PLA as well as PLGA nanoparticles in the intranasal pharmaceutical compositions exhibit enhanced penetration of methotrexate to the site of action, i.e. it exhibits enhanced penetration of methotrexate to the brain via the nasal route by increasing the residence time of the drug in methotrexate in the nasal cavity.

Preferably, the polymeric nanoparticles for use in the invention have an average particle size of less than or equal to 2000 nm. More preferably, the polymeric nanoparticles for use in the invention have an average particle size of less than or equal to 2000 nm, less than or equal to 500 nm and most preferably less than or equal to about 250 nm, or 200 nm.

The term average particle size as used herein refers to the average diameter of the particles.
The present invention thus provides intranasal pharmaceutical compositions comprising PLA as well as PLGA nanoparticles of methotrexate wherein such nanoparticles have an average particle size of less than or equal to about 2000 nm, preferably less than or equal to about 1000 nm, more preferably less than or equal to about 500 nm and most preferably less than or equal to about 250 nm.

The term average particle size as used herein refers to the average diameter of the particles.
Mostly, all particles have a particle size of less than or equal to about 500 nm, preferably less than or equal to about 200 nm.

The term “particles” as used herein refers to an individual particle of the polymeric nanoparticle comprising methotrexate or the polymeric nanoparticles comprising particles of methotrexate or the polymeric nanoparticles comprising methotrexate compositions and/or mixtures thereof.

The particles of the present invention can be obtained by any of processes such as but not limited to milling, precipitation, homogenization, high pressure homogenization, spray-freeze drying, supercritical fluid technology, double emulsion-solvent evaporation, emulsion-solvent evaporation, emulsion-solvent diffusion, PRINT (Particle replication in non-wetting templates), thermal condensation, ultrasonication, interfacial polymerisation, , spray drying and combinations thereof. Preferably, the particles of the present invention are prepared by the process of emulsion solvent evaporation with high pressure homogenization.

Preferably, the polymeric nanoparticles for use in the intranasal pharmaceutical compositions of the invention are prepared by, the process of solvent evaporation. This process can comprise dissolving methotrexate or other anti-cancer drugs and PLA/PLGA or other suitable polymers in suitable solvents followed by emulsification. The emulsion may then be subjected to high pressure homogenization and is further evaporated to produce methotrexate encapsulated PLA/PLGA nanoparticles or nanoparticles of other anti-cancer drugs encapsulated in PLA/PLGA or other suitable polymers.

Further, the methotrexate encapsulated PLA/PLGA nanoparticles are optionally freeze dried.

Alternatively, the process of solvent evaporation can comprise dissolving the one or more anti-cancer drugs such as methotrexate and one or more suitable polymers such as PLA/PLGA in suitable solvents followed by emulsification and evaporation to produce nanodispersions of the one or more anti-cancer drugs such as methotrexate which are further incubated with surface modifiers to form surface modified drug encapsulated PLA/PLGA nanoparticles.

The anticancer drug encapsulated PLA/PLGA nanoparticles obtained by the aforementioned processes may be formulated to obtain the desired nasal dosage form.

Accordingly, the anticancer drug encapsulated PLA/PLGA nanoparticles obtained by the aforementioned processes are co-precipitated in an aqueous stabiliser medium serving as gelling agent to obtain “one- pot” nanoparticulate dispersion. Further the obtained nanoparticles can be blended with gelling agents to obtain the nasal gel.

Suitable excipients may be used for formulating the nasal dosage forms according to the present invention.

Surfactants may be used in intranasal compositions of the invention which act as stabilizers to increase the stability of the composition. These are capable of stabilizing the particle thus inhibiting its aggregation and agglomerate formation. Further, they also enhance the BBB passage of the PLA/PLGA nanoparticles. Suitable amphoteric, non-ionic, cationic or anionic surfactants may be included in the pharmaceutical composition of the present invention.

Surfactants that can be used in the compositions of the invention may comprise one or more of, but not limited to non-ionic triblock copolymers or poloxamers (Synperonics®, Lutrols®, Pluronics® and Kolliphor®), Polysorbates, Sodium tauroglycolate, Sodium dodecyl sulfate (sodium lauryl sulfate), Lauryl dimethyl amine oxide, Docusate sodium, Cetyltrimethylammoniumbromide (CTAB), Polyethoxylated alcohols, Polyoxyethylenesorbitan, Octoxynol, N, N–dimethyldodecylamine–N–oxide, Hexadecyltrimethylammonium bromide, Polyoxyl 10 lauryl ether, Brij, Bile salts (sodium deoxycholate, sodium cholate), Polyoxyl castor oil, Nonylphenolethoxylate Cyclodextrins, Lecithin, Methylbenzethonium chloride. Carboxylates, Sulphonates, Petroleum sulphonates, alkylbenzenesulphonates, Naphthalenesulphonates, Olefin sulphonates, Alkyl sulphates, Sulphates, Sulphated natural oils and fats, Sulphated esters, Sulphated alkanolamides, Alkylphenols, ethoxylated and sulphated, Ethoxylated aliphatic alcohol, polyoxyethylenesurfactants, carboxylic esters Polyethylene glycol esters, Anhydrosorbitol ester and it's ethoxylated derivatives, Glycol esters of fatty acids, Carboxylic amides, Monoalkanolamine condensates, Polyoxyethylene fatty acid amides, Quaternary ammonium salts, Amines with amide linkages, Polyoxyethylene alkyl and alicyclic amines, N,N,N,N tetrakis substituted ethylenediamines 2- alkyl 1- hydroxyethyl 2-imidazolines, N -coco 3-aminopropionic acid/ sodium salt, N-tallow 3 -iminodipropionate disodium salt, N-carboxymethyl n dimethyl n-9 octadecenyl ammonium hydroxide, n-cocoamidethyl n-hydroxyethylglycine sodium salt or combinationsthereof.

Preferably, the surfactants may be present in an amount ranging from about 0.01% to about 20% by weight of the composition.

Solubilisers may also be used in the compositions of the invention. Solubilisers may be used to enhance the solubility of the anticancer agent and then encapsulate the solubilized anticancer agent in PLA/PLGA nanoparticles. Suitable solubilisers that may be used in intranasal compositions of the invention, include, but are not limited to polyethylene glycol, propylene glycol and their derivatives, Solutol HS, Caryol PGAMC, Transcutol P, Lauroglycol PGMC, hydrogenated fatty acid esters, coconut fatty acid diethanolamide,medium and/or long chain fatty acids or glycerides, monoglycerides, diglycerides, triglycerides, structured triglycerides, soyabean oil, peanut oil, corn oil, corn oil mono glycerides, corn oil di glycerides, corn oil triglycerides, polyethylene glycol, caprylocaproylmacroglycerides, caproyl 90, propylene glycol, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene castor oil derivatives, castor oil, cottonseed oil, olive oil, safflower oil, peppermint oil, coconut oil, palm seed oil, beeswax, oleic acid, long chain, medium chain and short chain fatty acids, long and medium chain triglycerides or combinations thereof.

Preferably, the solubilisers may be present in an amount ranging from about 0.01% to about 20% by weight of the composition.

Surface modifiers may also be used in the compositions of the invention. Surface modifiers enhance the BBB passage of the PLA/PLGA nanoparticles. Such surface modifiers that may be used in intranasal compositions of the invention, include, but are not limited to, polyethylene glycols and its derivatives (N-hydroxysuccinimide activated PEG, succinimidyl ester of PEG propionic acid, succinimidyl ester of PEG butanoic acid, and succinimidyl ester of PEG alpha-methylbutanoate and the like or mixtures thereof), propylene glyclos, poloxamers, polysorbates, Cetyltrimethylammoniumbromide (CTAB) or mixtures thereof.

Ligands may also be used in compositions of the invention. Ligands enhance the BBB passage of the PLA/PLGA nanoparticles as well as target the tumour cells. Such ligands that may be used in compositions of the invention, include, but are not limited to, folic acid, sugars, amines, antibodies, insulin, transferrin, diphtheria toxin or mixtures thereof in its own form or in conjugated form.

Suitable solvents/co-solvents or vehicles, that may be employed, in the pharmaceutical composition include, but are not limited to, dichloromethane, acetonitrile, ethyl acetate, acetone, propylene carbonate, water, glycerine, coconut fatty acid diethanolamide, medium and/or long chain fatty acids or glycerides, monoglycerides, diglycerides, triglycerides, structured triglycerides, soyabean oil, peanut oil, corn oil, corn oil mono glycerides, corn oil di glycerides, corn oil triglycerides, polyethylene glycol, caprylocaproylmacroglycerides, caproyl 90, propylene glycol, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene castor oil derivatives, castor oil, cottonseed oil, olive oil, safflower oil, peppermint oil, coconut oil, palm seed oil, beeswax, oleic acid, methanol, ethanol, isopropyl alcohol, butanol, acetone, methylisobutyl ketone, methylethyl ketone or combinations thereof.

Cryoprotectants for use in the compositions of the invention, may comprise one or more of sucrose, lactose, sorbitol, dextrose, trehalose, mannose, glycine, ammonium acetate, poloxamers and the like or combinations thereof.

Preferably, one or more cryoprotectants may be present in an amount ranging from about 0.5% to about 20% by weight of the total composition.

Thermosensitive bases as discussed above may be used in the compositions of the invention. Preferably, thermosensitive bases comprise one or more of poloxamers, carbopol, poly(N-isopropyl acrylamide) (PNIPAA), poly(N,N-diethylacrylamide) (PDEAA) poly(N-vinlycaprolactam) (PVCL), poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA)and polyethylene glycol (PEG), also called polyethylene oxide (PEO), PEG methacrylate polymers (PEGMA), poly methacrylic acid and its derivatives,and the like or combinations thereof.

Gelling agents may also be used in compositions of the invention. Suitable gelling agents, that may be employed, in the intranasal pharmaceutical compositions include, but are not limited to, carbomer, xanthan gum, sodium alginate (Manugel DMB), Carbopol®, polycarbophil, polysaccharides, natural gums, acacia, tragacanth, starch, cellulose derivatives such as carboxy methyl cellulose, hydroxyl propyl methyl cellulose, hydroxyl propyl ethyl cellulose (Methocel), methacrylate polymers, polyvinyl pyrrolidone, polyvinyl alcohol, bentonite, alginic acid, ethyl cellulose, gelatin, guar gum, hydroxyl ethyl cellulose, hydroxyl propyl cellulose, methylcellulose, hydroxyethyl methylcellulose, glycerylbehenate, sodium carboxymethylcellulose, algae extracts, gums, polysaccharides, polyethylene oxide, poloxamer (Pluronics®), pectins, hydrolysed proteins, magnesium aluminum silicate (Veegum®), polymers comprising pendant carboxylic acid groups, or esters thereof, polymers comprising pendant anhydrides of dicarboxylic acid groups and block co-polymers based on ethylene oxide and/or propylene oxide or combinations thereof.

The present invention also provides a method of treating brain tumours by administering intranasal pharmaceutical compositions comprising polymeric nanoparticles of methotrexate.

The present invention also provides the use in the treatment of brain tumours by administering intranasal pharmaceutical composition comprising polymeric nanoparticles of methotrexate.

The following examples are for the purpose of illustration of the invention only and is not intended in any way to limit the scope of the present invention.
Example:
A) Methotrexate PLA nanoparticles for intranasal administration
Sr. No Ingredients
Quantity
1 PLA
75mg-100mg
2 Methotrexate 20-25 mg

3 Poloxamer 188 1% solution (15 to 30 ml)

Process:
1. Methotrexate and the polymer were solubilized in dichloromethane.
2. The solution obtained in step (1) was emulsified with Poloxamer 188.
3. The emulsion obtained in step (2) was subjected to high pressure homogenization.
4. The organic solvent in the emulsion obtained in step (3) was evaporated and the residue was filled in the appropriate container and lyophilized and further processed into the desired nasal drug delivery formulations.
B) Methotrexate PLA nanoparticles for intranasal administration
Sr. No Ingredients
Quantity
1 PLA
75mg-100mg
2 Methotrexate 20-25 mg

3 Carbopol 934
0.1 to 0.5% (5 ml solution)

Process:
1. Methotrexate and the polymer were solubilized in dichloromethane.
2. The solution obtained in step (1) was emulsified with Carbopol 934.
3. The emulsion obtained in step (2) was subjected to high pressure homogenization.
4. The organic solvent in the emulsion obtained in step (3) was evaporated and the residue was filled in the appropriate container suitable and lyophilized and further processed into the desired nasal drug delivery formulations
.
In accordance the Methotrexate PLA nanoparticles obtained either through the process as exemplified in example (A) and (B) may be sniffed into the nasal cavity or reconstituted with a suitable solvent to be administered in the form of nasal spray or nasal drops.

It will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the spirit of the invention. Thus, it should be understood that although the present invention has been specifically disclosed by the preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and such modifications and variations are considered to be falling within the scope of the invention.
It is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

It must be noted that, as used in this specification and the appended claims, the singular forms "a," "an" and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "an excipient" includes a single excipient as well as two or more different excipients, and the like.
,CLAIMS:We Claims,

1. An intranasal pharmaceutical composition comprising one or more polymeric nanoparticles of one or more anti-cancer drugs and optionally one or more pharmaceutically acceptable excipients.
2. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more anti-cancer drugs comprise an alkylating agent, an anti-metabolite, an anti-microtubule agent, a topoisomerase inhibitor, an antitumor antibiotic, a DNA linking agent, a biological agent, a bisphosphonate, or any combination thereof.
3. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more anti-cancer drugs comprises an anti-metabolite.
4. An intranasal pharmaceutical composition according to any preceding claim, wherein the anti-metabolite comprises methotrexate.
5. An intranasal pharmaceutical composition according to claim 4, wherein methotrexate is in the form of a pharmaceutically acceptable derivative, optionally wherein the derivative is in the form of a pharmaceutically acceptable salt, solvate, hydrate, isomer, ester, anhydrate, enantiomer, polymorph, prodrug, tautomer or complex thereof.
6. An intranasal pharmaceutical composition according to any preceding claim, wherein the methotrexate is present in the composition in an amount of from 0.1% to 20% by weight of the composition.
7. An intranasal pharmaceutical composition according to any preceding claim , wherein the polymeric nanoparticles comprise poly-hydroxy acids, polyanhydrides, complex sugars such as hyaluronan, chitosan, inorganic polymers such as hydroxyapatite, polycaprylactones, polymalic acids, polybutylcyanoacrylates, sugars, dextrans, human serum albumin, bovine serum albumin, cellulose derivatives such as hydroxypropylcellulose, hydroxymethylcellulose, hydroxypropylmethylcellulose, methylcellulose polymers hydroxyethylcellulose, sodium carboxymethylcellulose, carboxymethylene, carboxymethylhydroxyethylcellulose, acrylics such as poly-acrylic acid, acrylamide, and maleic anhydride polymers; acacia, gum tragacanth, locust bean gum, guar gum, karaya gum, agar, pectin, carrageenan, gelatin, casein, zein and alginates, polyvinyl alcohol, carboxypolymethylene, bentonite, magnesium aluminium silicate, polysaccharides, modified starch derivatives and copolymers, or any combination thereof.
8. An intranasal pharmaceutical composition according to any preceding claim, wherein the polymeric nanoparticles comprises polylactic acid (PLA), polylacticglycolic acid (PLGA), or any combination thereof.
9. An intranasal pharmaceutical composition according to any preceding claim, wherein the polymeric nanoparticles are present in the composition in an amount of from 0.1% to 35% by weight of the composition.
10. An intranasal pharmaceutical composition according to any preceding claim, wherein the polymeric nanoparticles have an average particle diameter of less than or equal to 2000 nm.
11. An intranasal pharmaceutical composition according to any preceding claim, wherein the composition is in a nasal dosage form, optionally wherein the nasal dosage form comprises powders, powder for reconstitution, snuffs, sprays, solutions, suspensions, ointments, drops, in-situ gel, aerosols, ointments, microspheres, creams, gels, patches or films.
12. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more pharmaceutically acceptable excipients comprise one or more thermosensitive bases.
13. An intranasal pharmaceutical composition according to any preceding claim, wherein the thermosensitive base comprises poloxamers, carbopol, poly(N-isopropyl acrylamide) (PNIPAA), poly(N,N-diethylacrylamide) (PDEAA), poly(N-vinlycaprolactam) (PVCL), poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA), polyethylene glycol (PEG), PEG methacrylate polymers (PEGMA), poly methacrylic acid, poly methacrylic acid derivatives or any combination thereof.
14. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more pharmaceutically acceptable excipients comprise one or more surfactants, present in an amount of from 0.01% to 20% by weight of the composition.
15. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more pharmaceutically acceptable excipients comprise one or more solubilisers, present in an amount of from 0.01% to 20% by weight of the composition.
16. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more pharmaceutically acceptable excipients comprise one or more surface modifiers.
17. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more pharmaceutically acceptable excipients comprise one or more ligands.
18. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more pharmaceutically acceptable excipients comprise one or more solvents, cosolvents or vehicles, or combinations thereof.
19. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more pharmaceutically acceptable excipients comprise one or more cryoprotectants, present in an amount of from 0.5% to 20% by weight of the composition.
20. An intranasal pharmaceutical composition according to any preceding claim, wherein the one or more pharmaceutically acceptable excipients comprise one or more gelling agents.
21. An intranasal pharmaceutical composition, wherein the one or more anti-cancer drugs comprises methotrexate, the polymeric nanoparticles comprises polylactic acid (PLA) or polylacticglycolic acid (PLGA), and the one or more pharmaceutically acceptable excipients comprises one or more thermosensitive bases.
22. A process for preparing an intranasal pharmaceutical composition according to any preceding claim, wherein the process comprises formulating polymeric nanoparticles comprising one or more anti-cancer agents with one or more pharmaceutically acceptable excipients to provide the intranasal pharmaceutical composition.
23. A process according to claim 22, wherein the process comprises solvent evaporation.
24. A process according to claim 22 or claim 23, wherein the process comprises emulsifying the solution of the one or more anti-cancer drugs and one or more polymers with a solution of a thermosensitive base.
25. An intranasal pharmaceutical composition according to any one of claims 1 to 21, for use in the treatment of brain tumours, optionally wherein the brain tumours comprise glioblastomamultiforme (GBM) or anaplastic astrocytomas (AA).
26. Use of an intranasal pharmaceutical composition according to any one of claims 1 to 21, in the manufacture of a medicament for the treatment of brain tumours, optionally wherein the brain tumours comprise glioblastomamultiforme (GBM) or anaplastic astrocytomas (AA).
27. A method of treating brain tumours, wherein the method comprises administering an intranasal pharmaceutical composition according to any one of claims 1 to 21 to a patient in need thereof, optionally wherein the brain tumours comprise glioblastomamultiforme (GBM) or anaplastic astrocytomas (AA).
28. An intranasal pharmaceutical composition substantially as described herein.
29. A process for preparing an intranasal pharmaceutical composition substantially as described herein.

Dated this 13th day of December, 2014

Dr. P. Aruna Sree
(Regn.No.: IN/PA 998)
Agent for the Applicant
Gopakumar Nair Associates