A Novel RP-HPLC Method for the Simultaneous Determination of Lornoxicam and Paracetamol in API and Tablet Dosage Form

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 tablet dosage form. Isocratic RP-HPLC separation was achieved on a Varian Microsorb mv C₁₈ column (250 4.6 mm id, 5 mm particle size) using the mobile phase Water: Acetonitrile: Methanol: TEA (55:30:15:0.3) and pH adjusted to 7.25 pH with orthophosphoric acid at a flow rate of 2.0 ml/min. The retention time of lornoxicam and paracetamol were 3.334 and 1.483 min., respectively. The detection wavelength was 293 nm and samples of 20 μl were manually injected. The method was validated for linearity, precision, accuracy, robustness, and specificity. The method was linearity in the concentration range of 1–5 μg/ml for lornoxicam and 62.5–312.5 μg/ml for paracetamol. The limit of detection and limit of quantification for lornoxicam were 0.039 and 0.617 μg/ml, respectively, and for paracetamol 0.617 and 1.871 μg/ml, respectively. The accuracy (recovery) was found to be in the range of 99.71–100.95% for lornoxicam and 99.88–100.61% for paracetamol.