Separation and quantification of azelnidipine and chlorthalidone in a synthetic mixture using optimized HPTLC method

A simple, accurate, and reliable high-performance thin-layer chromatographic technique has been developed and validated for the simultaneous quantitation of azelnidipine and chlorthalidone in bulk and synthetic mixtures.

The procedure was carried out using a precoated silica gel 60 F254 TLC plate with a mobile phase of chloroform, ethyl acetate, and methanol in the ratio of 6.5:3.5:0.6 (by volume). Thin-layer chromatographic densitometry at 240nm was used to quantify medicines chromatographically.

Over concentration ranges of 250.0 to 1000.0ng/band for chlorthalidone and 160.0 to 640.0ng/band for azelnidipine, the high-performance thin-layer chromatography technique was quantitated. This technique produced a tight and well-resolved band at retention factors of 0.67±0.02 and 0.24±0.02 for azelnidipine and chlorthalidone, respectively. Data from a linear regression study calibrating this method revealed a strong linear correlation between the two approaches, with regression coefficients of r2>0.99 for both. According to The International Conference for Harmonization of Technical Requirements for Pharmaceuticals for Human Use requirements, the procedures were validated for precision, robustness, accuracy, and specificity.

The developed method was also used to simultaneously estimate azelnidipine and chlorthalidone in a synthetic mixture. The results were found to be in exemplary % assay with label claims.