A simple high-performance liquid chromatographic method for the determination of acyclovir in human plasma and application to a pharmacokinetic study.

A rapid, simple and sensitive reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the measurement of acyclovir (CAS 59277-89-3) concentrations in human plasma and its use in bioavailability studies is evaluated. The method was linear in the concentration range of 0.05-4.0 mu g/ml. The lower limit of quantification (LLOQ) was 0.05 mu g/ml in 0.5 ml plasma sample. The intra- and inter-day relative standard deviations across three validation runs over the entire concentration range were less than 8.2%. This method was successfully applied for the evaluation of pharmacokinetic profiles of acyclovir capsule in 19 healthy volunteers. The main pharmacokinetic parameters obtained were: AUC(0-t) 6.50 +/- 1.47 and 7.13 +/- 1.44 mu g.h/ml, AUC(0-infinity) 6.77 +/- 1.48 and 7.41 +/- 1.49 mu g.h/ml, C-max 2.27 +/- 0.57 and 2.27 +/- 0.62 mu g/ml, t(1/2) 2.96 +/- 0.41 and 2.88 +/- 0.33h, t(max) 0.8 +/- 0.3 and 1.0 +/- 0.5 h for test and reference formulations, respectively. No statistical differences were observed for C-max and the area under the plasma concentration - time curve for acyclovir. 90% confidence limits calculated for Cm and AUC from zero to infinity (AUC(0-infinity)) of acyclovir were included in the bioequivalence range (0.8-1.25 for AUC).