The present work describes development and validation of HPLC-PDA method for simultaneous estimation of Famotidine (FMO), Paracetamol(PAR), Chlorzoxazone (CZX) & Diclofenac potassium (DCL) in bulk powder and tablet formulation. In this method, chromatographic separation was achieved using C18 Phenomenex kinetex column (250 × 4.6mm id, particle size 5μm) as stationary phase with mobile phase comprising of 10mM sodium phosphate (Dibasic) buffer pH 2.82 adjusted with orthophosphoric acid : Acetonitrile (50:50 %v/v) with flow rate of 1.2ml/min in isocratic mode and eluents were monitored at 268nm. Linearity of method was studied & it was observed that the method was found to be linear in concentration range of 50-150% of labelled claim of each drug. The developed method was validated by different validation parameters. Accuracy of method was assessed by Multi level Recovery Studies by standard addition method at 80%,100% and120% resulted in recoveries of standard upto 100%±% RSD <2. The method was found to be precise for intraday, interday studies; the %RSD values were found to be <2. The method was found to be robust as there were no significant alterations on system suitability parameters by deliberately changing the parameters like pH of mobile phase, detection wavelength, flow rate, organic phase composition of mobile phase. The study concluded the validated HPLC- PDA method for analysis of complex mixture consisting of FMO, PAR, CZX and DCL in bulk and tablet dosage form.
