Rapid and simple determination of indinavir in serum, urine, and cerebrospinal fluid using high-performance liquid chromatography

A method for analysis of indinavir in serum, cerebrospinal fluid, and urine was developed. The method is based on liquid-liquid extraction followed by high performance liquid chromatography with UV detection. The method has a shorter analysis time than previously published methods, and it is sensiti ve enough to measure levels in all three fluids under routine clinical cond itions. The method is linear up to 32 mu mol/L, the limit of detection is 0 .01 mu mol/L, and recovery of the method is 86%. The interassay coefficient of variation at 2.0 mu mol/L was 2.8%, and no internal standard is needed. Over 700 clinical samples have been analyzed by this method, and concomita nt antiviral drugs do not interfere with the assay. Paroxetin and dipyridam ol are the only two compounds encountered to elute with retention times sim ilar to that of indinavir. Examples of chromatograms and a pharmacokinetic curve are given. The method is well suited for routine therapeutic drug mon itoring as well as for pharmacokinetic studies for research purposes.