A Modified and Cost-Effective HPLC Method for Determination of Plasma Concentrations of Rifampicin in Pulmonary TB Patients

Abstract

Objective: To evaluate the pharmacokinetics of standard doses of rifampicin (RMP) in fixed dose combination in pulmonary tuberculosis patients by a modified high performance liquid chromatography (HPLC) method Materials and Methods: This descriptive study was conducted after approval from Ethical Committee, Army Medical College Rawalpindi and was funded in part by National University of Sciences and Technology (NUST), Islamabad. Twenty adult patients with newly diagnosed pulmonary TB consented to participate in the study. RMP plasma concentrations were assayed by a simple and sensitive HPLC method in the initial phase of pulmonary tuberculosis treatment. The method was modified to use naproxen as an internal standard and validated according to International Conference on Hormonization (ICH) guidelines. Results: The calibration curve of rifampicin was linear within the range of 0.781–50 μg/ml. Both intra-day and inter-day variability and accuracy demonstrated good reproducibility at all quality control levels. The developed method was found to be simple, precise and accurate for estimation of rifampicin in plasma. The pharmacokinetic parameters of RMP showed marked inter-individual differences and sub-therapeutic levels. Conclusion: Evaluation of pharmacokinetics of standard doses of rifampicin in fixed dose combination in pulmonary tuberculosis patients by a modified high performance liquid chromatography (HPLC) method is precise, accurate and cost-effective. It may be used for monitoring plasma RMP levels in TB patients who are slow to respond or are non-responders and have less availability of resources.