DEVELOPMENT AND VALIDATION OF RP-HPLC AND ULTRAVIOLET SPECTROPHOTOMETRIC METHODS OF ANALYSIS FOR SIMULTANEOUS DETERMINATION OF PARACETAMOL AND LORNOXICAM IN PHARMACEUTICAL DOSAGE FORMS

A high performance liquid chromatographic and an UV spectrophotometric method were developed and validated for the simultaneous determination of paracetamol and lornoxicam in pharmaceutical formulations. The different analytical performance parameters such as linearity, precision, accuracy, specificity, limit of detection (LOD), and limit of quantification (LOQ) were determined according to International Conference on Harmonization (ICH) guidelines. HPLC was carried out by isocratic method on a reversed-phase C18 column and potassium dihydrogen phosphate buffer (pH adjusted to 3.5): acetonitrile (55:45, v/v) as eluent, at a flow rate of 1.0 mL/min. The UV spectrophotometric determinations were performed at 273 and 405 nm for paracetamol and lornoxicam, respectively. The linearity of the calibration curves for each analyte in the desired concentration range is good (r2 > 0.9997) by both the HPLC and UV methods. Both the methods were accurate and precise with recoveries in the range of 98 and 101% for the drugs and relative standard deviation (RSD) <5%. Moreover, the accuracy and precision obtained with HPLC correlated well with the UV method. However, UV spectroscopy can be an inexpensive, reliable, and less time consuming alternative for chromatographic analysis. The proposed methods are highly sensitive, precise, and accurate; hence, they were successfully applied for the reliable quantification of Active Pharmaceutical Ingredient (API) content in the commercial formulations of paracetamol and lornoxicam. Though the UV method is more practicable, the HPLC method shows application in stability indicating studies in addition to their assay.