Validation of a High-Performance Liquid Chromatography Method for the Assay of and Determination of Related Organic Impurities in Nevirapine Drug Substance

Abstract

Nevirapine (Viramune), a dipyridiodiazepinone, is a potent and highly specific nonnucleoside inhibitor of HIV-1 reverse transcriptase. This paper describes the validation of a specific, sensitive, and stability-indicating high-performance liquid chromatography method for the assay and determination of related organic impurities in nevirapine drug substance. This method uses a Supelcosil LC-ABZ column, a mobile phase of 20:80 (v/v) acetonitrile-25mM NH4H2PO4 (pH 5.0), and ultraviolet detection at a wavelength of 220 nm. This method was validated for specificity, linearity, accuracy, repeatability, detection limit, quantitation limit, stability of analyte solutions, robustness, and intermediate precision. Nevirapine is completely separated from all impurities. The method is shown to be linear with coefficients of determination r2 greater than 0.999. Average accuracy is 100.4% with a relative standard deviation of 0.7% for the assay. Accuracy ranges from 100.1 to 102.6% for related organic impurities. Repeatability is good, with relative standard deviations not more than 1.4%. The detection limit and the quantitation limit are determined to be 0.001 and 0.003%, respectively. Relative response factors of known organic impurities are determined, permitting the use of nevirapine at the 0.1% level as an external standard for the quantitation of these impurities. Analyte solutions are shown to be stable for at least 2 days at ambient temperature. The method is validated as robust, and intermediate precision is high. A system suitability test is developed and validated, and requirements are set.

Literature-Based Generation of Hypotheses on Chemical Composition Using Database Co-occurrence of Chemical Compounds

“…The actual sample contained 14 articles [17][18][19][20][21][22][23][24][25][26][27][28][29][30] covering 17 organic products (main components) and 67 impurities in them as a whole. These products are drugs (oxiracetam, 17 alevodopa and carbidopa, 18 almokalant, 20 ciprofloxacin, 21 tetracycline, 23 isosorbide 5-mononitrate, 24 ropinirole, 25 acetylsalicylic and ascorbic acids, 26 paracetamol, 26 nevirapine, 27 oxytetracycline, 28 and sildenafil); 30 a pharmaceutical synthetic precursor (2-acetylbenzothiophene); 22 a contrast enhancing agent for magnetic resonance (mangafodipir trisodium); 29 and a pesticide (chlortoluron). 19 For each impurity, rates of occurrence and co-occurrence with the corresponding main component were evaluated as the number of search answers in the Chemical Abstracts Plus database (CAS, Columbus, OH) with the use of a demo version of STN Easy network.…”

“…In nevirapine, 11 impurities were detected. 27 During the information retrieval, 34 co-occurring compounds were selected. The set of 11 highest RCRs was comprised from values of five impurities and six candidates for impurities.…”

“…Most co-occurrences can be explained by a few general reasons (Table 3). According to this classification, the articles [17][18][19][20][21][22][23][24][25][26][27][28][29][30] and other publications on determination of impurities in chemical products refer to pairs consisting of a main component and an impurity as constituents of the same "sample/mixture/solution/matrix" (Table 3). However, such analytical articles are rather few.…”

“…In this article, the approach of setting up identification hypotheses based on co-occurrence data will be tested for (a) a greater number of matrices and (b) a longer time covered by the full Chemical Abstracts Service (CAS) database. Co-occurrence of organic impurities determined in 17 chemical/pharmaceutical products [17][18][19][20][21][22][23][24][25][26][27][28][29][30] with these particular matrix compounds vs co-occurrence rates for several reference compound groups is studied. These data are used for the reverse prediction of the impurity composition of these chemical products.…”