ABSTRACT
Objective To prepare, investigate and optimize the drug stability of compound adapalene ointment.Methods The ointment containing adapalene and mupirocin were prepared with PEG400and PEG3350as matrix.Stress test was usedto evaluate and optimize the stability of drugs in the ointment.The drug stability was further tested by the acceleration test and long-term test.Results The raw adapalene was stable under high temperature, high humidity and strong light irradiation.The raw mupirocin was stable under high humidity and strong light irradiation, but was highly unstable under high temperature condition.Degradation of adapalene and mupirocin was found with pH≤7.At pH 7.5, the best stability was achieved, with over95％of the drugs remaining at day 10.Favorable ointment was prepared with PEG400∶PEG3350=2∶1.The drug stability was promoted by addition of 0.2％triethanolamine significantly.In the acceleration test and long-term test, the percentages of adapalene and mupirocin were above 95％.Conclusion The compound adapalene ointment was successfully prepared and the drug stability was excellent.