Crystalline form of sofpironium bromide and preparation method thereof
A cocrystal containing the 1′R-diastereomer and the 1′S-diastereomer of sofpironium bromide at a ratio of 1:3 (Form CO), a crystal mixture (for example, Form B) containing Form CO and a crystalline form of the 1′R-diastereomer (Form MN), and a method for preparing sofpironium bromide, which is suitable for manufacture of the crystal mixture are provided. Form CO and a crystalline form of sofpironium bromide containing Form CO (for example, Form B) have superior stability without hygroscopic property, and accordingly they can be preferably used as a raw material of medicaments.
1 . A stable crystal Form MN of a compound shown as formula I-a
characterized by showing peaks at 7.1±0.1, 21.4±0.1, 22.3±0.1, and 24.5±0.1 as diffraction angles 2θ in a powder X-ray diffraction spectrum.
2 . The crystal Form MN of claim 1 , wherein the crystal is not hygroscopic.
3 . The crystal Form MN of claim 1 , wherein the crystal form is a physicochemically stable crystalline form.
4 . The crystal Form MN of claim 1 , wherein the purity of the crystal form is not less than 98% w/w based on the content of the compound (I),
wherein the compound (I) is represented by the formula (I)
5 . The crystal Form MN of claim 1 , wherein a content of each compound represented by formulae III, IV and V
is not more than 0.5% w/w based on a content of compound (I),
wherein the compound (I) is represented by the formula (I)
6 . The crystal Form MN of claim 1 , wherein the total content of impurities is not more than 2.0% w/w based on a content of compound (I),
wherein the compound (I) is represented by the formula (I)
7 . A stable topical pharmaceutical composition comprising:
a pharmaceutically effective amount of the crystal Form MN of claim 1 as an active pharmaceutical agent in a pharmaceutically acceptable carrier.