HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF TRAMADOL IN PHARMACEUTICAL DOSAGE FORMS

A simpler specific and accurate high performance liquid chromatographi c (HPLC) method for determination of tramadol in pharmaceutical dosage forms has been developed. Reversed phase chromatography was conducted using mu-Bondapak C-18 column (3.9 x 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 monitore d on a UV detector at 230 nm. Each analysis required no longer than 8 minutes. Quantification was achieved by the measurement of the peak-ar ea ratio of the drug to the internal standard (metoclopramide) and the detection limit was 75 ng/mL. Linear response (r > 0.999) was observe d over the range of 0.1 - 10 mu g/mL and was run on 6 different occasi ons. There was no significant difference (p < 0.05) between inter- and intra- day studies for tramadol determined for two different concentr ations (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 t hat the drug is stable at 4, 25, and 50 degrees C for at least 4 weeks . The effect of light, 1 N HCl, and 1 N NaOH on the stability of trama dol has also been investigated.