Estimation of Losartan Potassium and Ramipril in Their Combined Dosage Form by Validated HPTLC Method

A sensitive, specific and precise high performance thin layer chromatographic method for estimation of Losartan potassium (LOS) and Ramipril (RAM) has been developed and validated. The method employed TLC aluminium plates pre-coated with silica gel 60 F-254 as the stationary phase. The solvent system consisted of toluene: methanol: ethyl acetate (6: 3: 2, v/v/v). This system was found to give compact and dense spots for LOS and RAM (R-f value 0.35 +/- 0.02 and 0.57 +/- 0.02, respectively). Densitometric analysis of drug was carried out in the absorbance mode at 210 nm. The method was validated with respect to linearity, specificity, precision, limit of detection, limit of quantification and recovery. The linear regression analysis data for the calibration plots showed a good linear relationship with R-2 = 0.9943 and 0.9963 for LOS and RAM respectively, in the concentration range of 200-1000 ng/spot for both the drugs. The LOD and LOQ were found to be 26.03 ng/spot and 78.88 ng/spot, respectively for LOS, 14.37 ng/spot and 43.56 ng/spot, respectively for RAM. Recovery of LOS and RAM were achieved in the range of 100.42-101.44 % and 100.80-102.41 %, respectively by developed method. Statistical analysis proves that the method is repeatable and specific for the estimation of LOS and RAM. Developed method was successfully applied for estimation of LOS and RAM in their combined dosage form.