Determination of acetaminophen and methocarbamol in bilayered tablets using RP – HPLC

A simple, specific and accurate reverse-phase liquid chromatographic method was developed for the simultaneousdetermination of acetaminophen and methocarbamol in bilayered tablet dosage form. A Develosil ODS-MG-5column having 100×4.6 mm internal dimensions, with mobile phase containing water: methanol: glacial aceticacid (60:40:1.5,v/v/v) was used. The effluent was monitored at 273 nm. The retention time of acetaminophen andmethocarbamol were found to be 1.846 and 4.713 min respectively. The linearity range for acetaminophen andmethocarbamol was 75-600 and 50-400 μg/ml with correlation values of 0.9998 and 0.999 respectively. The recoverywas found to be in the range of 98.28-99.96% for acetaminophen and 99.36-101.64% for methocarbamol. Theproposed method was found to be accurate, precise, and reproducible for the simultaneous analysis of thesedrugs in bilayered tablets.