A new sensitive and robust method development for estimation of tolcapone and quinapril in the bulk and formulations

Tolcopone and Quinapril are anti-hypersensitive drugs and, in combined dosages, are effective in managing hypertension. The RP-HPLC method was developed using OPA and Acetonitrile in 50:50 v/v as Mobile phase and 250*4.6mm, 5µ RP-HPLC column measured with a wavelength of 240nm. The HPLC system was fixed with a flow rate of 1.0ml/min; Both drugs, TOLCO and QUINA, were successfully detected at 2.153 and 3.203 min, respectively. The validation of the method as per ICH Linearity r2 lies at 0.999, and Precision, system suitability, and selectivity RSD values are within permissible limits. The accuracy of the process was found to be 99.73 and 99.52 for TOLCO and QUINA, respectively. The LOD 0.72 and 0.3 µl/ml and LOQ 0.84 and 0.13 µl/ml. The robustness and degradation studies show that the selected method is acceptable per the Guidelines.