title: A rapid and selective HPLC-UV method for the quantitation of efavirenz in plasma from patients on concurrent HIV/AIDS and tuberculosis treatments.
abstract: Owing to heterogeneity in therapeutic response, efavirenz is of research and clinical interest. There is a need to quantitate it using noncostly and selective methods. A method for efavirenz quantitation in plasma containing HIV and tuberculosis drugs was developed. Chromatographic separation was carried out using a C18 column. The mobile phase consisted of 0.1% formic acid and acetonitrile, and was pumped at a flow rate of 0.3 mL/min. Efavirenz and ritonavir (internal standard) were monitored at 247 nm. Plasma proteins were precipitated by centrifugation. The analysis time was 6 min. The response was linear (r = 0.9997). The accuracy ranged between 98 and 115% (intraday) and between 99 and 117% (interday). The precision ranged from 1.670 to 4.087% (intraday) and from 3.447 to 13.347% (interday). Recovery ranged from 98 to 132%. Stability ranged between 99 and 123%. The selectivity was proven by analysis of drugs used for the management of HIV/AIDS and tuberculosis. Plasma sample analysis showed an efavirenz retention time of 5.57 min and a peak plasma concentration of 2.4 µg/mL occurring at 2 h. This method is rapid and selective, and thus suitable for monitoring efavirenz in patients with HIV/AIDS alone or co-infected with tuberculosis in a less resourced setting.
authors.affiliation: Unit for Pharmacokinetics and Drug Metabolism, Department of Pharmacology, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden.
authors.forename: Emile
authors.initials: E
authors.lastname: Bienvenu
authors.forename: Kurt-Jürgen
authors.initials: KJ
authors.lastname: Hoffmann
authors.forename: Michael
authors.initials: M
authors.lastname: Ashton
authors.forename: Pierre Claver
authors.initials: PC
authors.lastname: Kayumba
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications / Q000188:drug therapy*; D000480:Alkynes; D048588:Benzoxazines / Q000097:blood* / Q000627:therapeutic use; D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000379:methods*; D003521:Cyclopropanes; D016903:Drug Monitoring / Q000191:economics / Q000379:methods*; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008297:Male; D018894:Reverse Transcriptase Inhibitors / Q000097:blood* / Q000627:therapeutic use; D013997:Time Factors; D014376:Tuberculosis / Q000150:complications / Q000188:drug therapy*
chemical_list: D000480:Alkynes; D048588:Benzoxazines; D003521:Cyclopropanes; D018894:Reverse Transcriptase Inhibitors; C098320:efavirenz
keywords: HPLC; efavirenz; plasma; quantitation