(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (10) International Publication Number (43) International Publication Date WO 2012/172413 Al 20 December 2012 (20.12.2012) P O P C T (51) International Patent Classification: (74) Agent: NAIR, Manoj Vasudevan; M/s Lex Orbis (Intel A61K 9/20 (2006.01) A61K 31/4453 (2006.01) lectual Property Practice), 709/710, Tolstoy House, 15-17 A61K 31/196 (2006.01) A61K 47/12 (2006.01) Tolstoy Marg, New Delhi 110 001 (IN). (21) International Application Number: (81) Designated States (unless otherwise indicated, for every PCT/IB20 12/00 1159 kind of national protection available): AE, AG, AL, AM, AO, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ, (22) Date: International Filing CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, DO, 15 June 2012 (15.06.2012) DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, (25) Filing Language: English HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP, KR, KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, ME, (26) Publication Language: English MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, (30) Priority Data: OM, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SC, SD, 1759/MUM/201 1 16 June 201 1 (16.06.201 1) IN SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. (71) Applicant (for all designated States except US) : ABBOTT HEALTHCARE PVT. LTD. [IN/IN]; 4, Corporate Park, (84) Designated States (unless otherwise indicated, for every Sion-Trombay Road, Mumbai 400 071, Maharashtra (IN). kind of regional protection available): ARIPO (BW, GH, GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, SZ, TZ, (72) Inventors; and UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, (75) Inventors/Applicants (for US only): MANE, Vidya TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, [IN/IN]; Abbott Healthcare Pvt. Ltd., c/o Piramal Life Sci EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, ΓΓ, LT, LU, LV, ences Limited, 1, Nirlon Complex, Goregaon (East), Mum MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, bai 400 063 (IN). PATIL, Prasad [IN/IN]; Abbott Health TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, care Pvt. Ltd., c/o Piramal Life Sciences Limited, 1, Nirlon ML, MR, NE, SN, TD, TG). Complex, Goregaon (East), Mumbai 400 063 (IN). GROVER, Manish [IN/IN]; Abbott Healthcare Pvt. Ltd., Published: c/o Piramal Life Sciences Limited, 1, Nirlon Complex, — with international search report (Art. 21(3)) Goregaon (East), Mumbai 400 063 (IN). JATHAR, Shri- — before the expiration of the time limit for amending the pad [IN/IN]; Abbott Healthcare Pvt. Ltd., c/o Piramal Life claims and to be republished in the event of receipt of Sciences Limited, 1, Nirlon Complex, Goregaon (East), amendments (Rule 48.2(h)) Mumbai 400 063 (IN). (54) Title: PHARMACEUTICAL COMPOSITION COMPRISING A COMBINATION OF EPERISONE AND DICLOFENAC AND PROCESS FOR PREPARING THEREOF (57) Abstract: The present invention relates to a pharmaceutical composition comprising a combination of eperisone or its pharma ceutically acceptable salts and diclofenac or its pharmaceutically acceptable salts and process for preparing thereof. PHARMACEUTICAL COMPOSITION COMPRISING A COMBINATION OF EPERISONE AND DICLOFENAC AND PROCESS FOR PREPARING THEREOF FIELD OF THE INVENTION: The present invention relates to a pharmaceutical composition comprising a combination of eperisone or its pharmaceutically acceptable salts and diclofenac or its pharmaceutically acceptable salts and process for preparing thereof. BACKGROUND OF THE INVENTION: Eperisone is chemically (2RS)-l-(4-ethylphenyl)-2-methyl-3-(l- piperidyl)propan-l-one, which is a centrally acting muscle relaxant. It acts by relaxing both skeletal muscles and vascular smooth muscles, and demonstrates a variety of effects such as reduction of myotonia, improvement of circulation, and suppression of the pain reflex. The drug inhibits the vicious cycle of myotonia by decreasing pain, ischaemia, and hypertonia in skeletal muscles, thus alleviating stiffness and spasticity, and facilitating muscle movement. Diclofenac is chemically 2-(2-(2,6-dichlorophenylamino)phenyl)acetic acid, which is a nonsteroidal anti-inflammatory drug (NSAID) that exhibits anti- inflammatory, analgesic, and antipyretic activities in animal models. The mechanism of action of diclofenac, like that of other NSAIDs, is not completely understood but may be related to prostaglandin synthesis inhibition. Diclofenac free acid is a benzene-acetic acid derivative. The usual approach in relieving muscle pain relies on trying to decrease muscle tone and breaking the pain-spasm-pain cycle. The basic pathologies of musculo¬ skeletal pain involve muscle spasm followed by pain, muscle relaxants are one of the drugs of choice in relieving it. Since pain in muscle spasm is one of the chief symptoms and is caused due to release of inflammatory mediators and sensitization of peripheral nociceptors, most guidelines recommend use of NSAID. NSAIDs are the most frequently prescribed medications worldwide and are widely used for patients with musculoskeletal pain. Although NSAIDs are devoid of any direct effect on skeletal muscle contraction, they are frequently used as a first-line treatment for conditions involving muscle pain. However both classes of drugs have limitations in the treatment of musculoskeletal pain which can be decreased by combining them together. In case of NSAIDs they are devoid of any direct effect on skeletal muscle contraction while on the other hand the mechanism of analgesia for skeletal muscle relaxants is not fully known. Combining an NSAID to muscle relaxant takes care of the limitation of both groups in relieving muscle pain. The combination would much more effectively break the pain-spam-pain cycle and allow faster mobilization and better relief. Treatment of spastic paralysis, in cerebrovascular diseases, spastic spinal paralysis, cervical spondylosis, post-op sequelae, spinal trauma, head injury, amyotrophic lateral sclerosis, cerebral palsy, spinocerebellar degenerations, spinal vascular diseases & other encephalomyelopathies. Improvement of myotonic conditions caused by the following diseases: neck-shoulder-arm syndrome, scapulohumeral periarthritis and low back pain. Some of the disclosed studies comprising eperisone and/or NSAIDs like diclofenac are described as below. U.S. Patent No. 5073375 relates to a pharmaceutical preparation for percutaneous administration containing eperisone or tolperisone or a salt thereof which exhibits excellent skin penetration, wherein the said pharmaceutical preparation comprises a monoglyceride of an aliphatic acid having 8 to 12 carbon atoms and an ester of lactic acid with an aliphatic alcohol having 12 to 18 carbon atoms or a monoglyceride of an aliphatic acid having 8 to 12 carbon atoms. U.S. Patent Application No. 20100029704 Al relates to a salt, particularly an ionic liquid which is a 1:1 salt, of a non-steroidal anti-inflammatory drug (NSAID) comprising a carboxylic acid and an organic amine compound, as well as a method of producing such a salt, wherein the said NSAID may be like diclofenac and the said organic amine compound may be like eperisone. The said salt compound is stable at ambient temperature, and shows an improved solubility in a liposoluble solvent. Therefore, it can increase the content of the carboxylic acid NSAID in an external preparation such as a patch and the like. As the result, transdermal absorbability and skin permeability of the efficacy ingredient can be enhanced. U.S. Patent Application No. 20100273746 A l relates to pharmaceutical formulation containing tolperisone or its pharmaceutically acceptable salts or tolperisone combined with a non-steroidal anti-inflammatory drug or their salts, gel forming macromolecule, solvent, and if required thickening agent, penetration enhancer and pH adjuvant or the mixture thereof. The invention also relates to the manufacturing process of the above mentioned pharmaceutical compositions, further the use of these formulations, particularly for transdermal treatment and the containers suitable for the dosage, which are dual compartment containers consisting of two separated chambers. PCT Application No. WO20 10 103544 A2 provides novel sustained release pharmaceutical preparations and process for making such compositions of tolperisone and/or eperisone and/or a pharmaceutically acceptable salt thereof. The present invention provides a sustained release formulation of tolperisone and eperisone either single or in combination or otherwise in combination with other drugs selected from the classes such as analgesic, antipyretic, neuroprotective agents, other muscle relaxants which can be formulated either in a fixed dose or as combination kit for oral administration. The composition is suitable for once a day administration into mammals and provides sustained and prolonged drug release till 24 hours which helps to reduce dosing frequency. The composition comprises therapeutically effective amount of active substance, release retarding polymers and other pharmaceutically acceptable excipients. None of the above cited prior arts comprising a combination of eperisone and NSAIDs relates to provide oral immediate release pharmaceutical composition. Moreover a mere combination of eperisone or its pharmaceutically acceptable salts and diclofenac or its pharmaceutically acceptable salts is incompatible and decrease the stability of the active ingredients, which causes not only decrease of the effective amount of the ingredients, but also change of external appearance during the course of time like change in the color of dosage form. The present inventors have surprisingly found that pharmaceutical composition comprising a combination of eperisone or its pharmaceutically acceptable salts and diclofenac or its pharmaceutically acceptable salts can be formulated as a single unit dosage form such as tablet. SUMMARY OF THE INVENTION; The present invention relates a pharmaceutical composition comprising a combination of eperisone or its pharmaceutically acceptable salts and diclofenac Or its pharmaceutically acceptable salts, wherein the said pharmaceutical composition is a unit dosage form.