Two-dimensional LC–MS/MS determination of antiretroviral drugs in rat serum and urine

A simple, rapid, reliable and highly sensitive on-line two-dimensional reversed-phase liquid chromatography–tandem mass spectrometric (2D-LC/MS/MS) method to determine antiretroviral drugs viz., abacavir (ABC), nevirapine (NVP) and indinavir (IDV) in rat serum and urine was developed and validated. The analytes were extracted on-line from rat serum and urine by a restricted access material (RAM) column and back-flushed into the reversed-phase C18 column for separation by LC. Detection was carried out by ESI-MS/MS. The developed method showed good selectivity, accuracy and precision for quantification of the antiretroviral drugs in rat serum and urine. Quantification limits for abacavir and nevirapine were 4.0 ng ml−1, whereas for indinavir 4.7 ng ml−1. The calibration graphs were linear in the range of 4–50 ng ml−1for abacavir, nevirapine and indinavir. The method was successfully applied to study the pharmacokinetics of antiretroviral in rats.