Development and validation of HPLC method for determination of indomethacin and its two degradation products in topical gel

The first method was finally chosen for validation because of the occurrence of placebo interferences in the case of using Zorbax SB-CN. System suitability parameters and validation parameters including method precision, accuracy, linearity, selectivity and robustness were set up. Afterwards, the method was successfully applied for the practical determination of indomethacin and its degradation products in a topical gel and for compound degradation control during stability studies.