Snow Brand Milk Products Co., Ltd.

Nippon Kayaku Kabushiki Kaisha

Nobuyoshi Honda

Kazuo Ohtsuki

Akikazu Mitsunobu

Satoshi Inoue

Yoshihiro Imaizumi

Makoto Yoshihama

Nobuaki Fujise

Yasushi Yamashita

Hiroaki Takaoka

Provided are stable hydrate crystals of 14.alpha.-hydroxy-4-androstene-3,6,17-trione having a biological activity of human placenta-originating estrodiene synthesis enzyme inhibitory action. These hydrate crystals include two kinds of 14.alpha.-hydroxy-4-androstene-3,6,17-trione hydrate crystals having a diffraction pattern having characteristic peaks at diffraction angles in crystalline powder X-ray diffraction. Processes for producing these hydrate crystals are also provided.

14.alpha.-hydroxy-4-androstene-3,6,17-trione hydrate and process for

14.alpha.-hydroxy-4-androstene-3,6,17-trione hydrate crystal and process

A remedy for endometriosis comprising, as an active ingredient, 14.alpha.-hydroxy-4-androstene-3,6,17-trione or an ester derivative thereof, can effectively treat endometriosis by the strong aromatase-inhibitory activity without giving serious side effects.

Treatment of endometriosis

Growing community of inventors

Ishibashi, Japan

Nobuyoshi Honda