Determination of salivary efavirenz by liquid chromatography coupled with tandem mass spectrometry

Abstract

a b s t r a c tA novel and robust screening method for the determination of the non-nucleoside reverse transcriptase inhibitor, efavirenz (EFV), in human saliva has been developed and validated based on high performance liquid chromatography tandem mass spectrometry (LC-MS/MS). Sample preparation of the saliva involved solid-phase extraction (SPE) on C18 cartridges. The analytes were separated by high performance liquid chromatography (Phenomenex Kinetex C18, 150 mm × 3 mm internal diameter, 2.6 m particle size) and detected with tandem mass spectrometry in electrospray positive ionization mode with multiple reaction monitoring. Gradient elution with increasing methanol (MeOH) concentration was used to elute the analytes, at a flow-rate of 0.4 mL/min. The total run time was 8.4 min and the retention times for the internal standard (reserpine) was 5.4 min and for EFV was 6.5 min. The calibration curves showed linearity (r 2 , 0.989-0.992) over the concentration range of 3.125-100 g/L. Mean intra-and inter-assay relative standard deviation, accuracy, mean extraction recovery, limit of detection (LOD) and limit of quantification (LOQ) were 0.46-9.43%, 80-120%, 60% (±7.95), 1.84 and 6.11 g/L respectively. The working range was defined as 6.25-100 g/L. This novel LC-MS/MS assay is suitable for reliable detection of low EFV concentrations in saliva and can be used as a screening tool for monitoring EFV compliance.

A sensitive and robust lc-ms/ms method with monolithic column and electrospray ionization for the quantitation of efavirenz in human plasma: application to a bioequivalence study

“…[38][39][40]44 This is critical for some applications such as pharmacokinetic studies that handle a large number of samples. Theron et al 44 described a method for quantification of EFZ in human saliva with a LLOQ of 6.11 ng mL -1 , but with a long analysis time 8.5 min.…”

“…[38][39][40]44 This is critical for some applications such as pharmacokinetic studies that handle a large number of samples. Theron et al 44 described a method for quantification of EFZ in human saliva with a LLOQ of 6.11 ng mL -1 , but with a long analysis time 8.5 min. Recent approaches applied to increase overall productivity in high-throughput applications include the use of simultaneous positive and negative electrospray ionization 41 and the use of ultra performance liquid chromatography (UPLC) for shorter analysis times.…”

Therapeutic Drug Monitoring of Antiretroviral Drugs in the Management of Human Immunodeficiency Virus Infection

“…Eliminating the need for medical personnel makes it possible to use this method in remote areas. To date, reports are available for the salivary ARV concentrations of efavirenz [86], nevirapine [73,85], indinavir [87,88], saquinavir [89], lopinavir [90] and maraviroc [91]. This tube contains a saliva collector impregnated with citric acid to stimulate saliva production, which some patients may find unpleasant to chew on for several minutes.…”

Evolution and Current Trends in Liquid and Supercritical Fluid Chromatography

“…Shell particles are a relatively recent trend in chromatographic separation, but several pharmaceutical-bioanalytical [105][106][107][108][109][110][111][112][113][114][115][116][117][118], food analytical [119][120][121][122][123][124][125][126][127][128][129], environmental [130][131][132][133][134] and multidimensional [135][136][137] separations can be found in the literature. Very recently, new commercially available wide-pore stationary phases demonstrate exceptional efficiency for protein separations [138][139][140].…”