Stability Studies on Solid Piperacillin Sodium with Stepped Humidity and Temperature Controlled Method

OBJECTIVE To establish the stepped humidity and temperature controlled method for stability study of solid drugs. METHODS The stepped humidity and temperature controlled method was used to study the degradation kinetics of piperacillin sodium. RESULTS The kinetic parameters of A, m and E_a obtained in the stepped humidity and temperature experi- ments were comparable with those obtained in the experiments at constant humidity and temperature. CONCLUSION The stepped humidity and temperature method was applicable to the stability study of piperacillin sodium. However, applications of the stepped humidity and temperature method to other solid drugs were uncertain.