Development of a single-tube, low-cost, analytical process to extract, separate and determine efavirenz and rifampicin plasma concentrations in HIV/TB co-infected patients

  • D Fox
  • R O’Connor
  • P Mallon
  • G McMahon
Open Access
Poster presentation


Rifampicin Efavirenz Resource Limited Setting Single Tube Quaternary Pump 
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Tuberculosis (TB) complicating HIV-1 infection is a persistent significant clinical concern, particularly in resource limited settings. Treatment of HIV-infected patients with TB often comprises efavirenz-containing antiretroviral regimens particularly when on TB treatment containing rifampicin. Although rifampicin may reduce EFV concentrations, little is known of the effect of the HIV virus or efavirenz on the pharmacokinetics of rifampicin, particularly in resource limited settings where the burden of disease exists. We aimed to develop a low-cost, simple analytical method for the accurate determination of efavirenz and rifampicin plasma concentrations.


Using high-performance liquid chromatography (HPLC) employing UV detection (1050 series quaternary pump, 1100 series autosampler, a diode array detector (DAD) and a 1200 series degasser), we developed and validated a single tube column-based assay for the detection of rifampicin and efavirenz. Data was acquired and analysed using Agilent Chemstation for LC 3D software.


Recovery for plasma samples spiked with the drugs were >90% for rifampicin and its metabolite deacetylrifampicin and >70% for efavirenz. Intra- and inter-assay precision relative standard deviation (RSD) values were <4% in all cases. The assay was validated on 300µl sample with a runtime of 10 minutes and both drugs measurable to concentrations of 100ng/mL.


This relatively easy, UV-based assay can accurately detect efavirenz and rifampicin concentrations within a clinically relevant concentration range using standard chromatography equipment, making it potentially applicable to resource limited settings.

Copyright information

© Fox et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Authors and Affiliations

  • D Fox
    • 1
  • R O’Connor
    • 2
  • P Mallon
    • 3
  • G McMahon
    • 1
  1. 1.School of Chemical SciencesDublin City UniversityDublinIreland
  2. 2.National Institute of Cellular BiotechnologyDublin City UniversityDublinIreland
  3. 3.HIV Molecular Research GroupUniversity College Dublin, School of Medicine and Medical SciencesDublinIreland

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