Quantitative determination of acyclovir in aqueous humor by LC-MS

A specific, sensitive and precise liquid chromatographic assay method was established using LC-MS for the determination of acyclovir (ACV) in aqueous humor (AH), which was directly injected onto an Inertsil ODS-3 C-18 column without any pretreatment. The Agilent 1100 series LC-MS system was operated under the electrospray ionization mode (ESI). The analyte was separated from endogenous substances with a mobile phase of methanol: water: acetic acid (5:95:0.1, v/v) at a flow-rate of 0.3mL min(-1). A linear response was observed over the concentration range from 5 to 50ng mL(-1) (r=0.9993). Intra- and inter-day coefficients of variation were in the ranges 5.2-9.0% and 5.8-8.2%, respectively. The recovery was > 91.0%, and the limit of detection was approximate 1 ng mL(-1). The pharmacokinetics of topically applied eye-drop and thermosetting gel were compared in rabbits utilizing the present method, the results demonstrated that LC-MS was a powerful tool for the detection of ACV in AH.