Simultaneous quantification of zidovudine, stavudine, lamivudine and nevirapine by Micellar Electrokinetic Capillary Chromatography Quantification simultanée de zidovudine, stavudine, lamivudine et névirapine par chromatographie électrocinétique micellaire

Purpose: Recent improvements to the availability of antiretroviral therapy in Sub-Saharan Africa can be attributed to the generic formulation of antiretroviral drugs. Quality drug surveillance, routine supervision and adherence data are however restricted owing to a fundamental lack of resources in the area. Accordingly we have developed an affordable micellar electrokinetic capillary chromatography (MEKC) method for the simultaneous detection and quantification of zidovudine, stavudine, lamivudine and nevirapine in plasma. Methods: The antiretroviral drugs were extracted by solid phase extraction. Various factors influencing separation of the four drugs have been optimized. A buffer consisting of 5 mM sodium tetraborate at pH 9.8, containing 50 mM SDS, 30% methanol and 5% ethanol was found to be particularly suitable and the MEKC method was validated. Results: All validation parameters were within the 20% acceptation limit, except for the interday precision of stavudine which required a daily calibration curve. The limit of quantification (LOQ) for zidovudine, stavudine, lamivudine and nevirapine were 0.037, 0.051, 0.029 and 0.028 mg/L respectively and were below the therapeutic concentration ranges of each drug. The optimized MEKC method was successfully applied to 16 human plasma samples. Conclusion: Our sensitive and validated method was demonstrated to be suitable for simultaneous detection and quantification of zidovudine, stavudine, lamivudine and nevirapine. This cost-effective method could be of interest for resource limited countries not only for adherence or therapeutic monitoring but also for steady-state pharmacokinetic studies of generic ARV drugs. Objectif : L’accès aux thérapies antirétrovirales en Afrique sub-saharienne s’est récemment nettement amélioré grace à l’apparition des antirétroviraux sous la forme de génériques. Cependant, la surveillance de la qualité des médicaments, le suivi thérapeutique de routine et les données concernant l’observance restent limités dans ces régions du fait du manque de ressources. Par conséquent, nous avons développé une méthode de chromatographie électrocinétique micellaire (CEM) à faible co t permettant la détection et la quantification simultanée de zidovudine, stavudine, lamivudine et névirapine dans le plasma. Méthodes : Une extraction en phase solide a été réalisée afin d’isoler les médicaments antirétroviraux. Différents facteurs influen ant la séparation des quatre composants ont été optimisés. Un tampon constitué de tétraborate de sodium 5 mM à pH 9,8, contenant 50 mM de SDS, 30 % méthanol et