LC Method for the Determination of Abacavir in Human Plasma for Pharmacokinetic Studies

A simple, rapid, sensitive, selective and high performance liquid chromatography method with MS/MS was developed and validated for determination of abacavir in human plasma. Extraction from the plasma was by liquid-liquid extraction. Tenofovir was used as the internal standard. The chromatographic separation was performed by Thermo C 18, 4.6 x 50 mm, 5 mu m column with mobile phase comprising of (phase pH 5 adjusted with acetic acid) ammonium acetate: acetonitrile (20:80 % v/v). The assay precision ranged from 2.1 to 4.3 and accuracy between 90.3 to 104.8 %, revealing that the method has good reproducibility over the concentration range 20 to 10000 ng mL(-1). The lower limit of quantitation is 20 ng/mL and the recovery of analyte and internal standard (IS) were found to be 62.86-63.62 % and 60.71-62.49 %. Frequently co administered drugs did not interfere with the described methodology. The proposed validated method is suitable to support a wide range of pharmacokinetic/bioequivalence studies.