Compressed Oxygen in Drug Stability Experiments

Abstract

A drug stability experiment accelerated by compressed oxygen was established. The stability of 10% ascorbic acid solution as a model was studied and the kinetic parameters were obtained with the newly established experimental method. Because ascorbic acid degrades under both anaerobic and aerobic conditions, the total rate constant k_total can be expressed as: k_total=k_anaerobic+k_aerobic, where k_anaerobic and k_aerobic are the rate con-stants of anaerobic and aerobic degradations, respectively. The k_anaerobic can be expressed as k_anaerobic=A_anaerobic·exp(−E_a,anaerobic/RT) according to Arrhenius equation, and the k_aerobic was found to be k_aerobic=A_aerobic·exp(−E_a,aerobic/RT)·pO₂ in our study.