Drying process for preparing crystalline solid famciclovir

a technology of crystalline solids and famciclovir, which is applied in the field of drying process for preparing crystalline solids of famciclovir, can solve the problems of affecting the ease with which the material is handled during processing, the inability to perform physicochemical characterization of either anhydrous or monohydrate forms, and the production of famciclovir

Inactive Publication Date: 2009-03-19
TEVA PHARM USA INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The process effectively produces high-purity crystalline famciclovir Form I with reduced solvent content, enhancing stability, handling, and bioavailability, while minimizing contamination from other forms.

Problems solved by technology

These patent publications state that the anhydrous form of famciclovir is prior art; however, there is no physicochemical characterization of either the anhydrous or monohydrate forms.
Accordingly, this may affect the flowability of the milled solid and hence affects the ease with which the material is handled during processing.
There are two problems regarding the production of famciclovir.
First, the drying procedure for famciclovir is difficult.
Second, it is difficult to obtain substantially pure crystalline solid famciclovir form I by convenient crystallization methods.

Method used

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  • Drying process for preparing crystalline solid famciclovir
  • Drying process for preparing crystalline solid famciclovir
  • Drying process for preparing crystalline solid famciclovir

Examples

Experimental program
Comparison scheme
Effect test

example 1

Drying in 0.25 Liter Stirred Reactor (30 Grams)

[0045]30 grams of wet famciclovir were washed with water. The material was dried in a stirred reactor. Form 1 was obtained. The following table describes the drying process and its conditions.

StartingWetnessmaterialDryingDryingDuring theSamplewetnessTemperaturetimedryingPressureStirring rateno.(%)(° C.)(Hours)process %(mmHg)(Rounds per minute)X111.174525.37012X24543.89X34561.77X4658.30X565210.03

example 2

Drying in 0.25 Liter (30 Grams)

[0046]30 grams of wet famciclovir were washed with water. The material was dried in a stirred reactor. Form 1 was obtained. The following table describes the drying process and its conditions.

StartingWetnessmaterialDryingDryingDuring theSamplewetnessTemperaturetimedryingPressureStirring rateno.(%)(° C.)(Hours)process %(mmHg)(Rounds per minute)Y19.84525.2393-96100Y24543.5392Y34561.889Y46580.289Y565210.0575

example 3

Drying in 0.25 Liter (30 Grams)

[0047]30 grams of wet famciclovir were washed with water. The material was dried in a stirred reactor. Form 1 was obtained. The following table describes the drying process and its conditions.

StartingWetnessmaterialDryingDryingDuring theSamplewetnessTemperaturetimedryingPressureStirring rateno.(%)(° C.)(Hours)process %(mmHg)(Rounds per minute)Z115.83301.0516.358912Z2301.4515.7392Z3303.0511.5292Z4304.459.1360Z5306.18.9460Z6458.54.5960Z7659.751.6260Z865220.0460

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Abstract

The present invention provides a drying process for preparing crystalline solid famciclovir form I comprising the steps of: i) preparing a wet crystalline form of famciclovir; ii) drying the wet crystalline form of famciclovir at a temperature of below 50° C. until the crystalline form contains less than 15% (wt / wt) wetness; and iii) drying the wet crystalline form of famciclovir at a temperature of above 50° C. until the wet crystalline form of famciclovir contains less than 0.05% (wt / wt) water to obtain crystalline solid famciclovir form I.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. patent application Ser. No. 11 / 131,119 filed May 18, 2005, which claims the benefit of U.S. Provisional Application Ser. No. 60 / 572,526, filed May 18, 2004, the disclosure of which is incorporated by reference.FIELD OF THE INVENTION[0002]The present invention relates to a drying process for preparing crystalline solid famciclovir.BACKGROUND OF THE INVENTION[0003]Famciclovir is an antiviral drug marketed by SmithKline Beecham and is available as Famvir®. Famvir® is indicated for the treatment of acute herpes zoster (shingles). It is also indicated for treatment or suppression of recurrent genital herpes in immunocompetent patients and for treatment of recurrent mucocutaneous herpes simplex infections in HIV infected patients. The chemical name for famciclovir is 2-[2-(2-amino-9H-purin-9-yl)ethyl]-1,3-propane diacetate.[0004]U.S. Pat. No. 5,246,937 discloses purine dervivatives including famciclovir ...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): C07D473/32
CPCC07D473/32A61P31/22
InventorEISEN-NEVO, HAGITMAIDAN-HANOCH, DALIA
OwnerTEVA PHARM USA INC