| US 7,473,780 B2 | ||
| Drying process for preparing crystalline solid famciclovir | ||
| Hagit Eisen-Nevo, Petah-Tikva (Israel); and Dalia Maidan-Hanoch, Kfar-Yona (Israel) | ||
| Assigned to Teva Pharmeceutical Industries Ltd., Petah Tiqva (Israel) | ||
| Filed on May 18, 2005, as Appl. No. 11/131,119. | ||
| Claims priority of provisional application 60/572526, filed on May 18, 2004. | ||
| Prior Publication US 2006/0004027 A1, Jan. 05, 2006 | ||
| Int. Cl. C07D 473/32 (2006.01) | ||
| U.S. Cl. 544—277 | 23 Claims |
| 1. A process for preparing crystalline famciclovir, comprising:
a) providing a wet crystalline form of famciclovir containing from about 15% to about 40% (wt/wt) solvent;
b) drying the wet crystalline form of famciclovir of step a) at a temperature of from about 30° C. to about 50° C. to obtain
a wet crystalline form of famciclovir; and
c) drying the wet crystalline form obtained from step b) at a temperature higher than 50° C. to obtain a crystalline form
of famciclovir containing less than 1% (wt/wt) solvent;
wherein the wet crystalline form of famciclovir obtained in step b) contains less than 15% (wt/wt) solvent.
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