RP-HPLC Method for Simultaneous Estimation of Calcipotriene and Betamethasone Dipropionte and Its Combined Dosage Form

This work is concerned with application of simple, accurate, precise and highly selective reverse phase high performance liquid chromatographic (RP-HPLC) method for simultaneous estimation of Calcipotriene and Betamethasone dipropionate in combined dosage form. Chromatographic separation was achieved isocratically at 25^oC on Zorbax SB-300 C₁₈ column (150 _ 4.6 mm) with a mobile phase composed of Methanol: 0.005M (NH₄)2PO₄ (pH 7.4)- Buffer in the ratio of 45:55 % v/v/v at flow rate of 1.0 ml/min. Detection is carried out using a UV detector at 264 nm. The retention time of Calcipotriene and Betamethasone dipropionate was found to be 7.99 min and 13.99 min. respectively. The method was found to be linear in the range of 0.8-1.4 _ppm with mean recovery of 101.16%+ 0.6 % for Calcipotriene and 100.29%+0.25 % for Betamethasone dipropionate. The correlation coefficients for all components are close to 1. The developed method was validated according to ICH guidelines and values of accuracy, precision and other statistical analysis were found to be in good accordance with the prescribed values. Thus the proposed method was successfully applied for simultaneous determination of Calcipotriene and Betamethasone dipropionate in routine analysis.