Composition containing benzamidine derivative and method for stabilizing benzamidine derivative

A solid composition comprising:

• a benzamidine derivative represented by any one of the chemical formulae (II) to (VIII) or a pharmacologically acceptable salt thereof;
• and
• at least one type of electrolyte selected from the group consisting of halide salts of alkaline metal or alkaline earth metal and alkaline metal salts or alkaline earth metal salts of perchloric acid:

A method for stabilizing a benzamidine derivative, comprising the step of:

• adding to a benzamidine derivative represented by the chemical formula (I) or a pharmacologically acceptable salt thereof, at least one type of electrolyte selected from the group consisting of halide salts of alkaline metal or alkaline earth metal and alkaline metal salts or alkaline earth metal salts of perchloric acid
• wherein R1 and R2 are the same as or different from each other and each represents a hydrogen atom, a methoxy group or an ethoxy group, X represents a hydrogen atom or a halogen atom, and Ar represents a phenyl group that may be substituted with one or not less than two substituents selected from the group consisting of a methyl group, an ethyl group, a methoxy group, an ethoxy group, a t-butyl group, a morpholinyl group, or a substituent represented by the following formula (XX),
• wherein, W represents CH or a nitrogen atom, A represents CH2 or a single bond, R3 represents a hydrogen atom or OR5, X represents CH2, an oxygen atom, a single bond or a carbonyl group, Y represents a single bond or a C1-4 alkyl group, R4 represents a hydrogen atom, OR6, a cyano group or COOR7, R5, R6 and R7 represent hydrogen atoms or C1-4 alkyl groups.

A method for stabilizing a benzamidine derivative, comprising the step of:

• adding to a benzamidine derivative represented by any one of the chemical formula (II) to (VIII) or a pharmacologically acceptable salt thereof at least one type of electrolyte selected from the group consisting of halide salts of alkali metal or alkaline earth metal and alkali metal salts or alkaline earth metal salts of perchloric acid: