Development and validation of stability indicating thin‐layer chromatography method for simultaneous estimation of Benidipine hydrochloride and Telmisartan

Abstract For the simultaneous estimation of Benidipine hydrochloride (BEN) and Telmisartan (TEL) in combined pharmaceutical dosage form, a stability‐indicating high‐performance thin‐layer chromatography (HPTLC) method has been developed and validated. It involves the use of HPTLC plates pre‐coated with silica gel 60F 254 and a mobile phase comprising of Methanol: Acetonitrile (1:9 v/v). The measurements of both drugs were performed at 237 nm. The drugs were subjected to acid‐alkali hydrolysis, photolytic, thermal, and oxidation degradation. The linearity of BEN was found to be between 200–1000 ng/band (R 2 = 0.9917), while for TEL, linearity was found to be between 2000 and 10000 ng/band (R 2 = 0.9979). The limit of detection and limit of quantitation were found to be 3.28 and 9.94 ng/spot for BEN and 158.79 and 481.17 ng/spot for TEL. The % relative standard deviation of the precision study was determined to be less than 2%. Various system suitability parameters were determined. The R f values of BEN and TEL were found to be 0.890 ± 0.0105 and 0.173 ± 0.0151, respectively. The resolution between BEN and TEL peak were found to be 4.48 and capacity factors were found to be 0.21 and 0.74 for BEN and TEL, respectively.