Comparative chromatography–mass spectrometry studies on the antiretroviral drug nevirapine—Analytical performance characteristics in human plasma determination

• We have compared three analytical techniques, i.e. GC–MS, LC–MS and LC–UV for the determination of nevirapine in human plasma.
• We have compared the performance of helium and hydrogen as carrier gases in GC–MS.
• Helium gave lower detection limits but comparable to hydrogen and both were found suitable for therapeutic drug monitoring.
• QuEChERS extraction technique gave good recoveries in both GC–MS and LC–MS.
• Analytical performance characteristics were the same or better than those obtaining in literature.

A contrast between the analytical performance characteristics using gas chromatography–mass spectrometry (GC–MS) liquid chromatography–mass spectrometry (LC–MS) and liquid chromatography–ultraviolet (LC–UV) detection for the determination of the antiretroviral drug (ARV) nevirapine (NVP) in fortified human plasma after QuEChERS extraction has been made. Analytical performance characteristics, i.e. linearities, instrument detection limits (IDLs), limits of quantitation (LOQs), method detection limits (MDLs), % mean recoveries and the corresponding relative standard deviations (%RSDs) were estimated using techniques above. Using GC–MS, the correlation coefficients (r2) were ≥0.990, which were deemed acceptable linearities. The MDLs ranged between 11.1–29.8 μg/L and 13.7–36.0 μg/L using helium and hydrogen carrier gases respectively. The LOQs ranged between 16.5–66.7 μg/L and 28.4–98.7 μg/L using helium and hydrogen carrier gases respectively with a % mean recovery of 83% and %RSD of 4.6%. Using LC–MS and LC–UV, the correlation coefficients (r2) were ≥0.990. The MDLs were ranged between 3.14 and 47.1 μg/L. The LOQs ranged between 2.85 and 90.0 μg/L respectively. The MDLs using GC–MS, LC–MS and LC–UV were below the therapeutic range for NVP in human plasma is considered to be between 2300 μg/L (Cmin) and 8000 μg/L (Cmax). This study also demonstrated that helium can be substituted with hydrogen which is relatively cheaper and easily obtainable even by use of a generator.