Development and Validation of A Sensitive and Rugged LC-MS/MS Method for Evaluation of Valganciclovir and its Active Metabolite Ganciclovir in Human Plasma

The current study was aimed to develop and validate a simple and sensitive method to quantify valganciclovir and its metabolite ganciclovir in human plasma using valganciclovir-D5, ganciclovir-D5 as internal standards for pharmacokinetic analyses. The method exhibited highly sensitive ranges 2-805 ng/ml for valganciclovir and 40-12000 ng/ml for ganciclovir. The analytes were extracted from plasma using solid phase extraction employing mixed-mode cation exchange cartridges. Valganciclovir and ganciclovir were separated using Agilent XDB-Phenyl column with a mobile phase consisting 35:65 ratio of 10 mM ammonium acetate in 0.3 % formic acid and acetonitrile at 0.60 ml/min flow rate with 2.50 min run time. The validated parameters were within the acceptance criteria as per the regulatory guidelines and the validated calibration curve (CC) ranges to both analytes have r value >0.99 with above 90 % recovery. The validated method was successfully used to study pharmacokinetics of orally administered valganciclovir (900 mg) in healthy male volunteers. The pharmacokinetic parameters were, Cmax 300 ng/ml for valganciclovir and 6000 ng/ml for ganciclovir, and tmax 0.50 h for valganciclovir and 1.00 h for ganciclovir.