2-[[[2-[(hydroxyacetyl)amino]-4-pyridinyl]methyl]thio]-N-[4-(trifluoromethoxy) phenyl]-3-pyridinecarboxamide benzene- sulfonate, crystals of same, polymorphs thereof, and processes for production thereof
In the development of 2-[[[2-[(hydroxyacetyl)amino] -4-pyridinyl]methyl]thio]-N-[4-(trifluoromethoxy)phenyl]-3- pyridinecarboxamide (compound (A)), there exist several complex problems: (1) compound (A) or salts thereof are difficult of recrystallization, said salts being considerably different in storage stability, and it is very difficult to obtain a salt of compound (A) having high storage stability； (2) in the crystallization process of compound (A), the control of polymorphism is very difficult； (3) compound (A) (in the free form) causes mineral deposition in the stomach when oral-administered repeatedly； and so on. In order to solve the problems, studies have been made with attention being paid to the kinds of salts. As a result, it has been found that benzensulfonate (salt) of compound (A) has the following properties: (1) in a one-week preliminary stability test (severe test), benzensulfonate of compound (A) is not decomposed by light, humidity, or other factors, thus being unproblematic in storage stability； (2) two kinds of crystal forms are prsent, and the crystal forms can be selectively produced by a certain method； and (3) no mineral deposition in the stomach is observed even after four-week repeated oral administration.
