Analysis of Generic Nevirapine Products in Developing Countries
- Scott R. Penzak, PharmD
- Edward P. Acosta, PharmD;
- Michele Turner
- Jorge A. Tavel, MD
- Henry Masur, MD
To the Editor: Combination antiretroviral therapy (CART) can dramatically improve the prognosis of patients with human immunodeficiency virus (HIV), but 90% of infected individuals worldwide do not have access to these drugs.1 Although generic drugs are now available in many countries at costs that are considerably lower than those of discounted proprietary agents, there have been anecdotal reports of generic antiviral medications that contain little or no active ingredients.2-3 As part of a quality-assurance investigation, we analyzed the content of several generic and proprietary antiretroviral formulations containing the non-nucleoside reverse transcriptase inhibitor nevirapine.
Methods
Tablets containing nevirapine (alone or in combination with other antiretroviral agents) were obtained from 6 international sources, representing 4 countries and 3 manufacturers (Table 1). Medications were obtained in April 2002 from physicians from South Africa, Zambia, Lithuania, and Kenya who were attending an HIV educational training program at the National Institutes of Health in Bethesda, Md. All tablets were obtained from local pharmacies. The nevirapine content of the 6 products was determined by high-performance liquid chromatography.4 Calibration and quality control standards of known concentrations were prepared for quantitative analysis from nevirapine pure standard provided by Boehringer-Ingelheim (Ingelheim, Germany). In total, 6 kinds of tablets were assayed with 6 replicates per tablet, comprising a total of 36 chromatographic injections; no 2 tablets originated from the same lot.
Table. Sources for Tablets Containing Nevirapine
Results
All nevirapine-containing products in this study were labeled as containing 200 mg of the drug. Nevirapine content and demographic data for the individual products are listed in Table 1. The average nevirapine content among the tested preparations was 197.9 mg (coefficient of variation [CV], 3.4%). Average accuracy of nevirapine content in tested preparations versus labeled amounts was 99.0%.
Comment
To our knowledge, these data represent the first published account of drug content among generic antiretroviral preparations. Although our sample size is small, the products were representative of the companies that supply the majority of this drug. Given relatively stringent manufacturing standards, it is unlikely that there would be significant variability between lots. Further studies documenting bioequivalence between generic and proprietary antiretroviral medications are necessary.
