A stability-indicating LC–MS/MS method for zidovudine: Identification, characterization and toxicity prediction of two major acid degradation products

Abstract

Zidvovudine (AZT) is a nucleoside analogue reverse transcriptase inhibitor (NRTI), a class of anti-retroviral drug. A stability-indicating assay method for AZT was developed in line with ICH guideline. Successful separation of AZT and its degradation products was achieved by gradient elution mode on reverse phase C18 column using 10 mM ammonium acetate: acetonitrile as the mobile phase at 0.8 mL/min flow rate, 25 µL injection volume, 30 °C column temperature and 285 nm detection wavelength. Two major acid degradation products were identified and characterized by liquid chromatography–electrospray ionization mass spectrometry (LC–ESI/MS/MS) and accurate mass measurements. The probable mechanisms for the formation of degradation products were identified based on a comparison of the fragmentation pattern of the [M + H] + ions of AZT and its degradation products. One of the degradation products, DP-1, was isolated by semi-preparative high performance liquid chromatography (HPLC) using Waters XBridge Prep C18 (250 mm×10 mm, 5 µm). Degradation products showed higher toxicity compared to the drug in some models assessed by TOPKAT software. The method validation was performed with respect to robustness, specificity, linearity, precision and accuracy as per ICH guideline Q2 (R1).

Overview of Forced Degradation Analysis for FDA Approved Antiretroviral agents: A Review

“…Antiviral medicines have been quantified using a variety of methods, including UV, capillary electrophoresis, and chromatographic methods such as GC and HPLC, LC-MS, and GC-MS. The authors of this review focus on stability, recommending HPLC/RP-HPLC technologies for the precise and effective development and validation of antiviral medicines such as Zidovudine, [15][16][17][18][19][20] Lamivudine, [20][21][22][23] Nevirapine, [24][25][26][27] Ritonavir, [28][29][30][31] Abacavir, [32][33][34] Efavirenz, [35][36][37][38] Tenofovir, [39][40][41] Fosamprenavir, [42][43][44][45][46] Atazanavir, [47][48] Emtricitabine, 35,35,39,49 Fosamprenavir, [42][43][44][45][46] Tipranavir, [50][51] Darunavir, [52]…”

Characterization of Impurities in Reverse Transcriptase Inhibitors by Profiling Techniques

“…In different models, the toxicity of degradation products was compared and estimated for AZT. [28] Didanosine Didanosine, also known ddI, which has trade names Videx and Videx EC, was the second FDA-approved ARV drug. It is an analog of adenosine.…”

Reverse Transcriptase Inhibitors Nanosystems Designed for Drug Stability and Controlled Delivery

“…The drug proved to decompose when exposed to light or under hydrolytic conditions, while it was more stable toward oxidation agents and thermal stress [65]. In particular, the acid degradation induced the formation of a pyrimidine derivative endowed with higher toxicity when compared to AZT, as demonstrated by a mutagenicity and an aerobic biodegradability assay [21]. Recently, three novel prodrugs of AZT, obtained by functionalization with dicarboxylic acids, were designed in order to enhance pharmacokinetics, chemical stability and affinity for human serum albumin [66].…”

“…Several of these clinically used drugs show an undesirable stability profile when exposed to stressing conditions either in solution or in solid form [20,21]. Similarly, stress tests have been performed on supramolecular systems in order to confirm any improved stability, under different conditions [22].…”