Determination of efavirenz in human plasma by high-performance liquid chromatography with ultraviolet detection.
Efavirenz is a non-nucleoside reverse transcriptase inhibitor for the treatment of the HIV infection. A simple, high-performance liquid chromatographic method has been developed and validated for the quantitative determination of efavirenz in human plasma. The method involved solid-phase extraction of the drug and the internal standard (L-737,354) from 300 microl of human plasma. The analysis was via UV detection at 250 nm using a reversed-phase C8 analytical column and a isocratic mobile phase consisting of phosphate buffer (pH 5.75)-acetonitrile that resolved the drug and internal standard from endogenous matrix components and potential coadministered drugs. Within- and between-day precisions were less than 8.6% for all quality control samples. The lower limit of quantification was 0.1 microg/ml. Recovery of efavirenz from human plasma was greater than 83%. This validated assay is being used in pharmacokinetic studies with efavirenz.
Saras-Nacenta
M
M
Clinical Pharmacology Service (UASP, Unitat d'Avaluació, Suport i Prevenció), Hospital Clinic, Barcelona, Spain. msarasa@clinic.ub.es
López-Púa
Y
Y
Lípez-Cortés
L F
LF
Mallolas
J
J
Gatell
J M
JM
Carné
X
X
D000480:Alkynes; D048588:Benzoxazines; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003521:Cyclopropanes; D006801:Humans; D010078:Oxazines / Q000097:blood* / Q000493:pharmacokinetics; D012015:Reference Standards; D015203:Reproducibility of Results; D018894:Reverse Transcriptase Inhibitors / Q000097:blood* / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
D000480:Alkynes; D048588:Benzoxazines; D003521:Cyclopropanes; D010078:Oxazines; D018894:Reverse Transcriptase Inhibitors; C098320:efavirenz