RP-HPLC Method for Simultaneous Estimation of Paracetamol and Drotaverine Hydrochloride in Pharmaceutical Formulations

A simple, sensitive and precise reverse phase high performance liquid chromatographic method (RP-HPLC) has been developed and validated for the simultaneous estimation of paracetamol and drotaverine hydrochloride in both : bulk drug samples and formulation. The method was carried out on a phenomenex Luna C-18 (250 mm × i.d -4.6 mm, particle size 5 µm) column with a mobile phase consisting of methanol : water (pH adjusted to 3.34 with 0. 1% ortho-phosphoric acid) in the ratio of 52 : 48 (v/v). The flow rate was optimized at 1 mL/min and effluent was monitored at detection wavelength of 246 nm. The total chromatographic run time was 10 minutes and the retention time of paracetamol and drotaverine hydrochloride was 3.18 min and 5.07 min, respectively. The method was proved to be accurate and precise at linearity range of 2-36 µg/mL for paracetamol and 1-60 µg/mL for drotaverine hydrochloride with a correlation coefficient (r2 ) 0.999 and 0.9991, respectively. The method is highly reproducible with recoveries ranging from 99.93-100.2% and 99.90-100.16% for paracetamol and drotaverine hydrochloride, respectively. The method was validated for accuracy, precision, robustness, detection and quantification limits as per ICH guidelines. The intra- and inter- day precision and accuracy values were found to be within the limits. Due to its simplicity, accuracy and economical value, the proposed method can be used for routine quality analysis of these drugs in bulk and combined dosage form.