1985 年 105 巻 5 号 p. 512-516
Kinetics of nafamstat mesilate in aqueous solution was studied and the following findings were obtained. In aqueous solution, nafamstat mesilate was exclusively hydrolyzed to form its moieties of 4-guanidinobenzoic acid and 6-amidino-2-naphthol. The hydrolysis followed a pseudo-first order reaction and was catalyzed by each hydrogen ion, hydroxyl ion and water depending on the pH conditions in the pH range of 1-7, the following the kinetic law of k0=kHαH+kH2O+kOHαOH. In the pH range of 3-9, the buffer concentration effect was observed. The ionic strength effect at pH 1 and 9 among pH 1, 3 and 9 studies was also observed. Nafamstat mesilate was most stable under acidic conditions, i.e. at pH 3.29 and 3.21 at 50°C and 60°C, respectively, as shown by pH-rate profile.