Determination of paracetamol and tramadol hydrochloride in pharmaceutical mixture using HPLC and GC-MS.

Two simple, rapid, and selective analytical procedures were developed for the simultaneous determination of paracetamol (PR) and tramadol hydrochloride (TR) in a binary mixture using high-performance liquid chromatography with UV detection (HPLC-UV) and gas chromatography with mass spectrometry (GC-MS) techniques. HPLC resolved the two compounds on a Hypurity Advance column using a mobile phase consisting of phosphate buffer pH 6.3 and acetonitrile (90:10, v/v). PR and TR were detected by their UV absorption at 220 nm. GC-MS involved separation of the two compounds using 100% dimethylpolysiloxane (Rtx-1) column with temperature programming. The EI mass spectrum of PR was characterized by [M](+) at 151 and a base peak at m/z 109 while TR mass spectrum was characterized by [M](+) at 263 and a base peak at m/z 58. Quantification of the analytes in both methods was based on measuring the peak areas. The reliability and analytical performance of the proposed methods including linearity, ranges, precision, accuracy, detection, and quantification limits were statistically validated. Calibration curves were linear over the range 10-400 microg/mL for both PR and TR using the HPLC method and over the ranges of 75-500 and 25-350 microg/mL for PR and TR, respectively, using the GC-MS method. The proposed methods were successfully applied for the determination of the two compounds in laboratory-prepared mixtures and in commercially available tablet formulation. No interference peaks were observed from common pharmaceutical adjuvants. The results compared favorably with those obtained by a derivative spectrophotometric method.