Diethylaminoethyl Ester of Benzylpenicillin : II. Rate of Hydrolysis in a Pharmaceutical Suspension

Abstract

The hydrolysis rate of the diethylaminoethyl ester of benzylpenicillin in a pharmaceutical suspension has been determined by a single contact partition method. The partition coefficients K of the pure ester, Kx of the partially hydrolyzed sample, and Kp of sodium penicillin G are calculated from ultraviolet absorption data. From these three experimental partition coefficients, the per cent of ester hydrolyzed at any interval is calculated by a suitable equation. Hydrolysis rate curves, representing 5°, 25°, and 37° studies, are plotted over a period of 168 hours.