High-Performance Liquid Chromatographic Method for Analysis of Emtricitabine in Rat Plasma: Method Development, Validation and Application to a Pharmacokinetic Study

A new reverse phase liquid chromatographic method for the investigation of emtricitabine in rat plasma was developed after oral administration to Wistar rats. The desired chromatographic separation was achieved on Phenomenex C18 column (250 mm × 4.6 mm I.D., 5 µm) column, under isocratic conditions using UV detection at 280 nm. The optimized mobile phase consisted of a mixture of 10 mM potassium dihydrogen phosphate buffer- (adjusted to pH 6.8) methanol-2% acetic acid in a ratio of (73 : 25 : 2, v/v/v) at a flow rate of 1 mL min−1. The system was found to produce sharp and well-resolved peaks for emtricitabine with retention time of 5.78 min. The linear regression analysis for the calibration curves showed a good linear correlation over the concentration range 0.050–3.0 µg mL−1, with determination coefficients, , exceeding 0.9970. The limits of detection (LOD) and quantitation (LOQ) were found to be 0.016 µg mL−1 and 0.049 µg mL−1, respectively. The method was successfully applied for the pharmacokinetic in rats. Emtricitabine concentration in plasma reached () was 1.357 µg mL−1 about 2 h after oral administration of 15 mg/kg/rat. The AUC0-24 was 12.175 µg mL−1* h and the apparent elimination half-life () was 8.153 h. This method was found to be suitable for examining emtricitabine concentration in rats, after oral administration of emtricitabine in a single dose.