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.