Adhikari Sarju, Rustum Abu M
Boehringer Ingelheim Animal Health USA Inc. (BIAH), 631 US Route 1 South, North Brunswick, NJ 08902, USA.
Boehringer Ingelheim Animal Health USA Inc. (BIAH), 631 US Route 1 South, North Brunswick, NJ 08902, USA.
J Pharm Biomed Anal. 2022 Jun 5;215:114767. doi: 10.1016/j.jpba.2022.114767. Epub 2022 Apr 14.
Eprinomectin (EPM) is a semi-synthetic potent antiparasitic drug widely used in veterinary medicine. In this study, a comprehensive forced degradation study was carried out on EPM drug substance as per ICH guidelines. Generation of adequate quantities of major degradation products of EPM via forced degradation studies was necessary for identification, structure elucidation, and understanding its degradation mechanism and degradation pathways. EPM drug substance was subjected to acid, base, oxidation (HO and KCrO), thermal (solid and solution state), and photolytic (solid and solution state) stress degradation. The degradation products (DPs) formed in the stressed degraded samples were successfully separated using a gradient elution on a HALO C18 column (100 × 4.6 mm, 2.7 µm). Mobile phase A consisted of water and mobile phase B consisted of ethanol/isopropanol (98/2, v/v). A total of six major DPs of EPM drug substance formed under various stress conditions. The chemical structures of DPs were determined using liquid chromatography-high resolution mass spectrometry (LC-HRMS) and characterized through comparison of their fragmentation profile with EPM B using tandem mass spectrometry (MS/MS). Additionally, two solvates (methanol adduct B #1 and methanol adduct B #2) were observed during the acid-stressed degradation study of EPM in presence of methanol. To confirm the chemical structure, these products were isolated with semi-preparative HPLC and characterized by using a combination of LC-MS/MS and nuclear magnetic resonance spectroscopy. The elucidated chemical structure of the degradation products of EPM was also justified through mechanistic explanations. Identification and characterization of the DPs including degradation mechanism(s) of EPM should facilitate the understanding of the stability behavior of EPM drug substances as well as aid in the design of new formulations made with EPM.
依普菌素（EPM）是一种半合成的高效抗寄生虫药物，广泛应用于兽医学领域。在本研究中，按照国际人用药品注册技术协调会（ICH）指南对依普菌素原料药进行了全面的强制降解研究。通过强制降解研究生成足够量的依普菌素主要降解产物，对于其鉴定、结构解析以及了解其降解机制和降解途径是必要的。依普菌素原料药分别进行了酸、碱、氧化（过氧化氢和重铬酸钾）、热（固态和溶液态）以及光解（固态和溶液态）应激降解。在HALO C18柱（100×4.6 mm，2.7 µm）上采用梯度洗脱成功分离了应激降解样品中形成的降解产物（DPs）。流动相A为水，流动相B为乙醇/异丙醇（98/2，v/v）。在各种应激条件下共形成了依普菌素原料药的六种主要DPs。使用液相色谱-高分辨率质谱（LC-HRMS）确定了DPs的化学结构，并通过串联质谱（MS/MS）将其碎片图谱与依普菌素B进行比较来进行表征。此外，在依普菌素于甲醇存在下的酸应激降解研究中观察到了两种溶剂化物（甲醇加合物B #1和甲醇加合物B #2）。为确认化学结构，这些产物通过半制备高效液相色谱进行分离，并结合LC-MS/MS和核磁共振光谱进行表征。还通过机理解释对依普菌素降解产物阐明的化学结构进行了论证。依普菌素降解产物的鉴定和表征，包括其降解机制，应有助于了解依普菌素原料药的稳定性行为，并有助于设计含依普菌素的新制剂。
