Trace Level Quantification of the (-)2-(2-amino-5-chlorophenyl)-4-cyclopropyl-1,1,1-trifluoro-3-butyn-2-ol Genotoxic Impurity in Efavirenz Drug Substance and Drug Product Using LC-MS/MS

Trace Level Quantification of 4-Methyl-1-nitrosopiperazin in Rifampicin Capsules by LC-MS/MS

Rifampicin is a first-line anti-tuberculosis drug. However, in August 2020, the presence of 1-methyl-4-nitrosopiperazine (MNP), a nitrosamine impurity, was detected by the United Stated Food and Drug Administration (US FDA) in rifampicin capsules. Consequently, the development of efficient methods for the detection of MNP is an important objective. In this study, the MNP present in rifampicin capsules was detected using LC-MS/MS. A total of 27 batches from nine manufacturers in the Chinese market were tested, with MNP (0.33–2.36 ppm) being detected in all samples at levels exceeding the maximum acceptable intake limit of 0.16 ppm initially set by the FDA. However, after considering the associated benefits and risks, the FDA-approved limit was revised to 5 ppm; hence, all the samples examined herein exhibited MNP levels well below the required limit. Furthermore, the results of forced degradation experiments suggest that MNP is formed by the thermal degradation of rifampicin.

A Concise Analytical Profile of Efavirenz: Analytical Methodologies

Non-nucleoside reverse transcriptase inhibitors are the prime members of antiretroviral therapy that are presently employed for the management of the human immunodeficiency virus. It uses an enzyme i.e., reverse transcriptase to convert its ribonucleic acid into reverse transcription; these agents impede the function of reverse transcriptase and reverse transcription counter human immunodeficiency virus from replicating. Efavirenz is the first-generation non-nucleoside reverse transcriptase inhibitor agent. Similar to the other non-nucleoside reverse transcriptase inhibitor agents; it is prescribed with other inhibitors in combination for regimens antiretroviral therapy. To enhance survival and avoid aggressive infections in patients affected with human immunodeficiency virus infection, adequate antiretroviral therapy is the most significant treatment. Accordingly, the development and validation of such therapeutic agents are challenging work for the analysts. Therefore, the proposed review integrally addresses the analytical reports of efavirenz recorded in the literature databases like Scopus, Web of Science, Google Scholar, Pub-Med, and through many other sources. It has been remarked that for the development of efavirenz many analytical techniques were used for addressing the qualitative and quantitative estimation of efavirenz from various pharmaceutical and biological matrices. This review plan to review the stereochemistry, mechanism of action, resistance, pharmacokinetics, pharmacodynamics, safety and adverse reaction, and various analytical approaches assessed for the same. The hyphenated and chromatographic techniques are frequently used for analysis of cited drug.

Low-level determination of 4-chlorobutyl-(S)-[4-chloro-2-(4-cyclopropyl-1,1,1-trifluoro-2-hydroxy-but-3yn-2-yl)phenyl] carbamate (4-CTHC) in efavirenz drug substance by LC-MS

A rapid, simple, sensitive, and selective liquid chromatography-tandem mass spectrometry (LC-MS) test method was developed and validated for the trace level determination of 4-chlorobutyl-(S)-[4-chloro-2-(4-cyclopropyl-1,1,1-trifluoro-2-hydroxy-but-3yn-2-yl)phenyl] carbamate (4-CTHC). 4-CTHC is a potential genotoxic impurity in efavirenz drug substance and the acceptable level is 2.5 μg ml^-1 with respect to analyte concentration according to ICH M7(R1) Multidisciplinary Guidelines M7(R1). The LC-MS/MS analysis of 4-CTHC impurity was carried out on a Kinetex C₁₈ (150 × 4.6 mm, 5.0 μm) column. In this test procedure, the mobile phase was prepared with buffer (0.1% formic acid in water) and acetonitrile in the ratio of 1:3 (v/v). The method set flow rate was 0.4 ml min^-1 . The method was developed with a short run time of <10 min. Selective ion monitoring acquisition mode and negative polarity electrospray ionization mode were used as an MS method to quantify genotoxic impurities at 422.25 Da. The method showed linearity in a range of 0.64-3.71 μg ml^-1 with a correlation coefficient of 0.9992. The RSD for intra-day and inter-day precision was found to be <5%. The method's accuracy was in the range of 106.5-112.4% for the genotoxic impurity of 4-CTHC. The procedure was validated as per the current ICH Q2 (R1) guidelines and proved suitable for stability testing in the quality control laboratory for pharmaceutical preparations.