High Performance Liquid Chromatographic Determination of Tramadol in Pharmaceutical Dosage Forms

Abstract

A simple, specific and accurate high performance liquid chromatographic (HPLC) method for determination of tramadol in pharmaceutical dosage forms has been developed. Reversed phase chromatography was conducted using (.μ-Bondapak C₁₈ column (3.9 × 150 nm) with an isocratic mobile phase consisting of 0.005 M triethylamine in 0.01 M sodium phosphate buffer (pH 5.5) containing 17% acetonitrile. The effluent was monitored on a UV detector at 230 nm. Each analysis required no longer than 8 minutes. Quantification was achieved by the measurement of the peak-area ratio of the drug to the internal standard (metoclopramide) and the detection limit was 75 ng/mL. Linear response (r > 0.999) was observed over the range of 0.1 – 10 μg/mL and was run on 6 different occasions. There was no significant difference (p < 0.05) between inter- and intra- day studies for tramadol determined for two different concentrations (0.5 and 5.0 mg/mL). The mean relative standard deviations (RSD%) of the results of within-day precision and accuracy of the drug was < 7%. The stability of tramadol at different temperatures indicated that the drug is stable at 4, 25, and 50°C for at least 4 weeks. The effect of light, 1 N HCl, and 1 N NaOH on the stability of tramadol has also been investigated.