Validation of a sensitive LC/MS/MS method for the determination of zidovudine and lamivudine in human plasma

摘要

A sensitive LC/MS/MS assay for determining zidovudine (ZDV) and lamivudine (3TC) in human plasma was validated to support antiretroviral pharmacology research programs. After addition of stable labeled isotopic zidovudine (ZDV-IS) and lamivudine (3TC-IS) as internal standard, a solid phase extraction was performed with an Oasis HLB 1cc cartridge, with recoveries of 92.3% for ZDV and 93.9% for 3TC. A Phenomonex Synergi Hydro-RP (2.0 × 150 mm) reversed phase analytical column was utilized for chromatographic separation. Mobile phase consisted of an aqueous solution of 15% acetonitrile and 0.1% acetic acid. Detection was accomplished by ESI/MS/MS in the positive ion mode, monitoring 268/127 and 271/130, and 230/112 and 233/115 transitions, for ZDV and ZDV-IS and 3TC and 3TC-IS, respectively. The method was linear from 1 to 3000 ng/mL with a minimum quantifiable limit of 1 ng/mL when 100 μL of plasma were analyzed. Validations results demonstrated high accuracy (≤ 8.3% deviation) and high precision (≤ 10% CV) for the quality control samples. The method was also shown to be specific and reproducible. The value of the high sensitivity was demonstrated by quantitation of approximately 100 existing samples that had ZDV below the limit of quantitation using a previously validated, less sensitive HPLC-UV method utilized in the laboratory.