Development and validation of a reversed-phase HPLC method for the determination of γ-tocotrienol in rat and human plasma

γ-Tocotrienol (γ-T3) is a member of the vitamin E family. Recently, γ-T3 has attracted the attention of the scientific community due to its potent anticancer activity and other therapeutic benefits. The objective of this study was to develop and validate a simple and practical reversed-phase HPLC method with satisfactory sensitivity for the routine quantification of γ-T3 in rat and human plasma. The separation of γ-T3 from the plasma components was achieved with a C₁₈ reversed-phase column with an isocratic elution using a mixture of methanol, ethanol and acetonitrile (85:7.5:7.5, v/v/v) with a UV detection at 295nm. γ-T3 was extracted from rat and human plasma by liquid-liquid extraction with an average recovery of 60%. The method proved linear in the range 100-5000ng/mL. The inter-day precision ranged from 5.8 to 12.8% and the accuracy ranged from 92.4 to 108.5%, while the intra-day precision ranged from 0.7 to 7.9% in both rat and human plasma. This data confirm that the developed method has a satisfactory sensitivity, accuracy and precision for the quantification of γ-T3 in plasma. To assess its applicability the method was successfully applied to the quantitative analysis for pharmacokinetic studies of γ-T3 in rats administered a 10mg/kg single oral dose.