Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D405/00—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom
  • C07D405/02—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom containing two hetero rings
  • C07D405/12—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom containing two hetero rings linked by a chain containing hetero atoms as chain links
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P25/00—Drugs for disorders of the nervous system
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P25/00—Drugs for disorders of the nervous system
  • A61P25/24—Antidepressants

Definitions

• the present invention relates to a process for the preparation of a pharmaceutically active compound, and to the use of the so-prepared compound in therapy.
• this invention is concerned with a new process for the preparation of a paroxetine chloride propan-2-ol solvate and its use to prepare a crystalline anhydrate form of paroxetine hydrochloride.
• Paroxetine hydrochloride has been described in the literature as a crystalline hemihydrate (see EP-A-0223403 of Beecham Group) and as various crystalline anhydrate forms (see WO96/24595 of SmithKline Beecham).
• WO96/24595 describes the preparation of the form A anhydrate via an intermediate solvate with an organic solvent such as propan-2-ol.
• paroxetine hydrochloride propan-2-ol solvate When prepared conventionally (crystallisation from anhydrous propan-2-ol), paroxetine hydrochloride propan-2-ol solvate has very poor stirring properties, and is very difficult to isolate, wash, and dry. It is also very difficult to desolvate by heat treatment under vacuum. In WO96/24595, the problem that conventional drying techniques were incapable of efficient removal of solvent was addressed by providing an additional displacement stage before the product was finally dried.
• the present invention is based on the finding that crystallisation of paroxetine hydrochloride from a mixture of propan-2-ol and a co-solvent produces an improved crystalline form which is much easier to stir, filter, wash and dry. Surprisingly it has also been found that it is easier to remove solvent of crystallisation by heat treatment.
• the present invention provides a process for the preparation of paroxetine hydrochloride propan-2-ol solvate which comprises forming a solution of paroxetine hydrochloride in a mixture of propan-2-ol and an effective co-solvent, and crystallising paroxetine hydrochloride propan-2-ol solvate from the solution.
• an effective cosolvent is one which will form a clear solution when added to a solution of paroxetine hydrochloride in propan-2-ol and which does not form a competing solvate during crystallisation.
• Suitable cosolvents include toluene, heptane and hexane. Surprisingly toluene has been found to be particularly useful despite the fact that a toluene solvate of paroxetine hydrochloride can exist.
• the cosolvent mixture may formed before addition of paroxetine hydrochloride, or by addition of a cosolvent to a solution of paroxetine hydrochloride in propan-2-ol, or by addition of propan-2-ol to a solution of paroxetine hydrochloride in an effective cosolvent.
• the final stage of the preparation of paroxetine hydrochloride is carried out in an effective cosolvent, to which propan-2-ol may be added for crystallisation in accordance with the invention.
• toluene is used as the cosolvent it can be used conveniently in the preceding manufacturing step. After washing and acidification, only partial evaporation is necessary, followed by addition of propan-2-ol and crystallisation.
• Crystallisation may be initiated by conventional procedures such as cooling a heated solution, or removing solvent by evaporation or heating. It may be advantageous to add seeds of crystalline paroxetine hydrochloride propan-2-ol solvate prepared by the procedure of this invention or by the procedure of WO96/24595.
• a crystalline anhydrate of paroxetine hydrochloride may be formed by heating the propan-2-ol solvate to remove bound propan-2-ol.
• the resultant product desirably contains less than 2% of the solvated solvent, preferably less than 1%, more preferably less than 0.5%o, and most preferably less than 0.1%>.
• the crystalline product is the Form A anhydrate of paroxetine hydrochloride.
• the crystalline paroxetine hydrochloride product of this invention may be formulated for therapy as described in EP-A-0223403 or WO96/00477.
• paroxetine product of this invention includes treatment of: alcoholism, anxiety, depression, obsessive compulsive disorder, panic disorder, chronic pain, obesity, senile dementia, migraine, bulimia, anorexia, social phobia, premenstrual syndrome (PMS), adolescent depression, trichotillomania, dysthymia, and substance abuse, referred to below as "the disorders”.
• the disorders include treatment of: alcoholism, anxiety, depression, obsessive compulsive disorder, panic disorder, chronic pain, obesity, senile dementia, migraine, bulimia, anorexia, social phobia, premenstrual syndrome (PMS), adolescent depression, trichotillomania, dysthymia, and substance abuse, referred to below as "the disorders”.
• the present invention also provides: a pharmaceutical composition for treatment or prophylaxis of the disorders comprising paroxetine hydrochloride anhydrate prepared by this invention and a pharmaceutically acceptable carrier;
• paroxetine hydrochloride anhydrate prepared by the process of this invention to manufacture a medicament for the treatment or prophylaxis of the disorders
• a method of treating the disorders which comprises administering an effective or prophylactic amount of paroxetine hydrochloride anhydrate prepared by this invention to a person suffering from one or more of the disorders.
• Paroxetine hydrochloride hemihydrate 160 g was suspended in a mixture of toluene (250 mil) and isopropanol (1000 ml) and heated to boiling. Solvent was removed by distillation and replaced by fresh isopropanol (3 x 500 ml). The boiling point was then 81.2°C. Further solvent was removed by distillation until the volume was about 1000 ml. The well stirred mixture was allowed to cool to about 70°C, then hexane (500 ml) was added slowly to give a clear solution at 57°C. Seeds of paroxetine hydrochloride isopropanol solvate were added, and as the crystallisation proceeded the temperature increased to 60°C. Stirring was continued until the temperature had fallen to about 30°C, then the product was collected, washed on the filter with hexane (2 x 500 ml) and dried in vacuo at ambient temperature.
• Paroxetine hydrochloride hemihydrate (122 g) was suspended in toluene (1000 ml) and heated to reflux for 2 hours under Dean & Stark apparatus to remove water. The toluene solution was concentrated to approximately 250 ml volume at which point it was still mobile and easy to stir. Warm propan-2-ol was added (1300 ml at about 50°C) and the reaction mixture stirred vigorously; the mixture crystallised slowly but did not become unstirrable.
• paroxetine hydrochloride containing approximately 1.6% propan-2-ol.
• a conventionally prepared sample of solvate heated overnight in a vacuum oven at 70°C for 24 hours contained 4.1% propan-2-ol.
• Paroxetine hydrochloride hemihydrate 50 g was heated to reflux with stirring in toluene (500 ml) and the water removed using a Dean and Stark apparatus. The solution was allowed to cool to about 40°C, diluted with isopropanol (200 ml), and allowed to crystallize at ambient temperature. The product was collected, washed with toluene and dried at 40°C to give paroxetine hydrochloride isopropanol solvate.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Biomedical Technology (AREA)
• Neurology (AREA)
• Neurosurgery (AREA)
• Veterinary Medicine (AREA)
• General Chemical & Material Sciences (AREA)
• Public Health (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Pharmacology & Pharmacy (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Psychiatry (AREA)
• Pain & Pain Management (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Plural Heterocyclic Compounds (AREA)

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• 1997
  • 1997-12-19 GB GBGB9726907.0A patent/GB9726907D0/en not_active Ceased
• 1998
  • 1998-12-18 AP APAP/P/2000/001836A patent/AP2000001836A0/en unknown
  • 1998-12-18 EP EP98962563A patent/EP1042318A1/de not_active Withdrawn
  • 1998-12-18 BR BR9813638-0A patent/BR9813638A/pt not_active Application Discontinuation
  • 1998-12-18 AU AU17698/99A patent/AU1769899A/en not_active Abandoned
  • 1998-12-18 HU HU0004503A patent/HUP0004503A3/hu unknown
  • 1998-12-18 CN CN98811920A patent/CN1281448A/zh active Pending
  • 1998-12-18 JP JP2000525421A patent/JP2001526288A/ja active Pending
  • 1998-12-18 WO PCT/GB1998/003836 patent/WO1999032484A1/en not_active Ceased
  • 1998-12-18 SK SK924-2000A patent/SK9242000A3/sk unknown
  • 1998-12-18 CA CA002315066A patent/CA2315066A1/en not_active Abandoned
  • 1998-12-18 KR KR1020007006764A patent/KR20010033317A/ko not_active Withdrawn
  • 1998-12-18 OA OA1200000182A patent/OA11635A/en unknown
  • 1998-12-18 ID IDW20001158A patent/ID24733A/id unknown
  • 1998-12-18 TR TR2000/01933T patent/TR200001933T2/xx unknown
  • 1998-12-18 IL IL13659098A patent/IL136590A0/xx unknown
  • 1998-12-18 PL PL98341358A patent/PL341358A1/xx unknown
  • 1998-12-18 EA EA200000689A patent/EA200000689A1/ru unknown
• 2000
  • 2000-06-16 NO NO20003145A patent/NO20003145L/no not_active Application Discontinuation
  • 2000-07-13 BG BG104604A patent/BG104604A/xx unknown

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