Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D211/00—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings
  • C07D211/04—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
  • C07D211/06—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members
  • C07D211/08—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms
  • C07D211/18—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms with substituted hydrocarbon radicals attached to ring carbon atoms
  • C07D211/20—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms with substituted hydrocarbon radicals attached to ring carbon atoms with hydrocarbon radicals, substituted by singly bound oxygen or sulphur atoms
  • C07D211/22—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms with substituted hydrocarbon radicals attached to ring carbon atoms with hydrocarbon radicals, substituted by singly bound oxygen or sulphur atoms by oxygen atoms
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K31/00—Medicinal preparations containing organic active ingredients
  • A61K31/33—Heterocyclic compounds
  • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
  • A61K31/435—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with one nitrogen as the only ring hetero atom
  • A61K31/44—Non condensed pyridines; Hydrogenated derivatives thereof
  • A61K31/445—Non condensed piperidines, e.g. piperocaine

Definitions

• This invention relates to an amorphous form of fexofenadine hydro- chloride, to a process for the preparation thereof, and to a composition containing it.
• fexofenadine is 4-[4-[4-hdroxydiphenylmethyl)-1-piperidin- yl]-hydroxybutyl]- ⁇ , ⁇ -dimethylbenzene acetic acid also known as terfenadine carboxylic acid metabolite having the Formula I.
• Fexofenadine hydrochloride (Terfenadine carboxylic acid hydrochlor- ide) is an effective antihistamine which avoids adverse effects associated with the administration of terfenadine including abnormal heart rhythms in some patients with liver disease or who also take the antifungal drug ketoconazole or the antibiotic erythromycin.
• polymorphism we mean to include different physical forms, crystal forms, crystalline/liquid crystalline/non- crystalline (amorphous) forms. This has especially become very interesting after observing that many antibiotics, antibacterials tranquiiizers etc, exhibit polymorphism and some/one of the polymorphic forms of a given drug exhibit superior bio-availability and consequently show much higher activity compared to other polymorphs. It has also been disclosed that the amorphous forms in a number of drugs exhibit different dissolution characteristics and in some cases different bioavailability patterns compared to the crystalline form [Konne T., Chem. Pharm.
• EP 490648 and EP 022527 also deal with the subject of polymorphism in drugs.
• PCT patent application WO 95/31437 discloses fexofenadine hydrochloride in various new crystalline forms designated Form I, Form II and Form IV and methods for their preparation.
• the first object of the present invention is to provide fexofenadine hydrochloride in an amorphous form.
• the amorphous form of fexofenadine hydrochloride is prepared by an efficient process which uses conditions which are convenient to operate on a commercial scale and operationally safe.
• the second object of the present invention is to provide a process for the preparation of fexofenadine hydrochloride in an amorphous form which comprises dissolving crystalline fexofenadine hydrochloride in a suitable solvent or dissolving fexofenadine base in a suitable solvent and adding a suitable solvent containing hydrogen chloride and recovering amorphous form of fexofenadine hydrochloride from the solution thereof by spray drying or freeze drying technique.
• a pharmaceutical composition comprising fexofenadine hydrochloride in an amorphous form with one or more pharmaceutical carriers and/or excipients.
• fexofenadine hydrochloride is recovered from the solution in an amorphous form using a freeze drying technique.
• the freeze dryer (Model : Virtis Genesis SQ Freeze - Dryer), which is used, operates on the principle of lyophilization, i.e., a process of stabilizing initially wet materials (aqueous solution or suspensions) by freezing them, then subliming the ice while simultaneously desorbing some of the bound moisture (primary drying). Following disappearance of the ice, desorp- tion may be prolonged (secondary drying). This process is preferably conducted under vacuum.
• fexofenadine hydrochloride is recovered from the solution in an amorphous form using a spray drying technique.
• the Mini-Spray Dryer (Model : Buchi 190, Switzerland) which is used, operates on the principle of nozzle spraying in a parallel - flow, i.e., the sprayed product and the drying gas flow in the same direction.
• the drying gas can be air or inert gases such as nitrogen, argon and carbon dioxide. Nitrogen is preferred in this case.
• suitable solvent means lower alkanol or combination of lower alkanol, ester, ketone, chlorinated solvent and mixture (s) thereof.
• Lower alkanol includes those primary, secondary and tertiary alcohols having from one to six carbon atoms.
• Suitable lower alkanol solvents include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, amyl alcohol and t-butanol.
• ketone or ester includes solvents having from one to ten carbon atoms such as acetone, methyl ethyl ketone, 2-butanone, 4- methylpentan-2-one, ethyl acetate or n-butylacetate.
• suitable chlorinated solvents include dichloromethane, chloroform or carbon tetrachloride. Mixture of these solvents are also contemplated.
• Amorphous fexofenadine hydrochloride prepared according to the process of the present invention may be characterized by its infra-red spectrum in KBr disc ( Figure 1 ) and by its X-ray powder diffraction pattern
• Fexofenadine hydrochloride crystalline (124g, 0.231 moles) was dissolved in methanol (300ml) at 25-30 s C. The clear solution so obtained was subjected to spray drying in a Mini-Spray Dryer (Buchi Model 190) and fexofenadine hydrochloride in an amorphous form was isolated (114g).
• X-ray powder diffraction pattern ( Figure 2) shows a plain halo thus demonstrating the amorphous nature of the product. Infrared spectrum in KBr ( Figure 1 ) is different than the one obtained for crystalline form of fexofenadine hydrochloride ( Figure 3).
• Example 1 The process of Example 1 was repeated with fexofenadine hydrochloride (10g, 0.0186moles) using ethylacetate (20ml) and methanol
• Example 1 The process of Example 1 was repeated with fexofenadine hydrochloride (10g, 0.0186 moles) using acetone (20ml) and methanol (20ml) instead of methanol to give amorphous fexofenadine hydrochloride (8.9g).
• IR (KBr) spectrum and x-ray crystallography examination confirmed the amorphous nature of the product.
• Fexofenadine (15gm, 0.0299 moles) was suspended in methanol (60 ml) and to it was added isopropanol containing equivalent molar hydrogen chloride to get a clear solution.
• the clear solution was subjected to spray drying in a mini spray dryer (Buchi Model 190) and fexofenadine hydrochloride in an amorphous form was isolated (14.9g).
• IR (KBr) and x-ray crystallography revealed that the product was amorphous.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Organic Chemistry (AREA)
• Medicinal Chemistry (AREA)
• Pharmacology & Pharmacy (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

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• 1999
  • 1999-05-25 IN IN776DE1999 patent/IN191492B/en unknown
• 2000
  • 2000-05-25 WO PCT/IB2000/000708 patent/WO2000071124A1/en not_active Application Discontinuation
  • 2000-05-25 AU AU46040/00A patent/AU4604000A/en not_active Abandoned
  • 2000-05-25 EP EP00927651A patent/EP1185266A4/de not_active Withdrawn

Patent Citations (6)

Non-Patent Citations (1)

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