New method was established for simultaneous estimation of Clindamycin and Clotrimazole by RP-HPLC method. The chromatographic conditions were successfully developed for the separation of Clindamycin  and Clotrimazole by using ACE C18 column (4.6×150mm) 5µ, flow rate was 1.2 ml/min, mobile phase ratio was (70:30 v/v) methanol:Phosphate buffer pH 3 (pH was adjusted with orthophosphoricacid), detection wavelength was 240nm. The instrument used was Waters HPLC Auto Sampler, Separation module 2690, photo diode array detector 996, Empower-software version-2. The retention times were found to be 2.344 mins and 3.284 mins. The % purity of Clindamycin and Clotrimazole was found to be 101.27% and 99.97% respectively. The system suitability parameters for Clindamycin  and Clotrimazole such as theoretical plates and tailing factor were found to be 4668, 1.3 and 6089 and 1.2, the resolution was found to be 6.0. The analytical method was validated according to ICH guidelines (ICH, Q2 (R1)). The linearity study n Clindamycin and Clotrimazole was found in concentration range of 50µg-250µg and 5µg-50µg and correlation coefficient (r²) was found to be 0.999 and 0.999, % recovery was found to be 99.56% and 99.48%, %RSD for repeatability was 0.2 and 0.2, % RSD for intermediate precision was 0.2 and 0.1respectively. The precision study was precise, robust, and repeatable.LOD value was 3.17 and 5.68, and LOQ value was 0.0172 and 0.2125 respectively. Hence the suggested RP-HPLC method can be used for routine analysis of Clindamycin and Clotrimazole in API and Pharmaceutical dosage form.

KEYWORDS: ACE C18 column, Clindamycin  and Clotrimazole, RP-HPLC