Simultaneous Determination of Lornoxicam and Paracetamol in API and in Synthetic Mixture by Reverse Phase High Performance Liquid Chromatography

A simple, precise, and accurate isocratic RP-HPLC method was developed and validated for determination of Lornoxicam (LOR) and Paracetamol (PCM) in bulk drug and synthetic mixture. The isocratic RP-HPLC separation was achieved on a Varian Microsorb mv C18 column (250 4.6 mm id, 5 μm particle size) using the mobile phase Water: Acetonitrile: Methanol: TEA (40:30:30:0.3) pH adjusted to 7.3 with orthophosphoric acid at a flow rate of 1.5 ml/min. The retention time of Lornoxicam and Paracetamol were 3.44 and 1.83 min., respectively. The detection was performed at 293 nm and samples of 20 μl were manually injected. The method was validated for linearity, precision, accuracy, robustness and specificity. The method was linear in the concentration range of 2–30 μg/ml with a correlation coefficient of 0.9993 for Lornoxicam and 2–100 μg/ml with a correlation coefficient of 0.9994 for Paracetamol. The Calculated LOD and LOQ for Lornoxicam were 0.032 and 0.099 μg/ml, respectively and for Paracetamol 0.360 and 1.09 μg/ml, respectively. The accuracy (recovery) was found to be in the range of 99.74– 100.85% with RSD of 0.55% for Lornoxicam and 99.93–100.17% for Paracetamol with RSD of 0.88%.