Patent Number: 6,169,108

Title: Anhydrous crystals

Abstract: An anhydrous crystal of a compound represented by the formula: R.sup.2 --CH.sub.2 CONH--R.sup.1 wherein R.sup.1 represents a substituted or non-substituted pyridyl group or substituted or non-substituted phenyl group and R.sup.2 represents a substituted or non-substituted 2-oxo-1-pyrrolidinyl group, characterized in that said crystal is substantially free from hygroscopicity. For example, by drying a hydrous crystal of said compound at a temperature of C. or above under reduced pressure, an anhydrous crystal is provided that exhibits a weight increase of 1% or less when stored under the relative humidity of 83% at the temperature of C. for 30 days. By using the anhydrous crystal for the manufacture of a medicament comprising the compound as an active ingredient, a product with a constant content of the active ingredient can be obtained.

Inventors: Sato; Yukio (Tokyo, JP), Kitaoka; Hiroaki (Tokyo, JP), Terada; Tatsuya (Tokyo, JP), Ono; Makoto (Tokyo, JP)

Assignee: Daiichi Pharmaceutical Co., Ltd.

International Classification: C07D 207/00 (20060101); C07D 207/27 (20060101); A61K 031/40 (); C07D 207/27 ()

Expiration Date: 01/02/2018