White analytical chemistry–aligned eco-friendly, stability-indicating HPLC and HPTLC methods for simultaneous estimation of efonidipine hydrochloride ethanolate and chlorthalidone

Efonidipine hydrochloride ethanolate and chlorthalidone is used to treat hypertension. However, no stability-indicating HPLC or HPTLC method has been reported for the concurrent analysis of these FDC products. The study aims to develop and validate robust stability-indicating HPLC and HPTLC methods for the concurrent quantification of EHE and CTD. Different optimized mobile phases used for the effective separation and quantification of drugs in the presence of degradation products. The validation parameters were evaluated as per ICH guidelines. The HPLC method used a phosphate buffer (pH-3.5 adjusted with OPA), methanol, and acetonitrile (50:30:20, v/v/v) and HPTLC method with toluene: ethyl acetate: methanol (6:2:1, v/v/v) as the mobile phase. Results of validation studies showed excellent method performance with forced degradation studies. The stability indicating HPLC and HPTLC methods are sensitive, precise, and eco-friendly. They provide solutions for the quality control and regulatory compliance of antihypertensive formulations.