Arkansas Laboratory, Office of Regulatory Affairs, U.S. Food and Drug Administration, Jefferson, AR 72079, United States.
Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, United States.
Int J Pharm. 2020 Mar 30;578:119077. doi: 10.1016/j.ijpharm.2020.119077. Epub 2020 Jan 24.
Identification and quantification of excipient related degradation products in the liposomal formulation is important, as they may impact the safety and efficacy of the drug. Phospholipids are one of the major excipients in liposome drugs composing the lipid bilayer, and they are vulnerable to oxidation and hydrolysis reactions. Since phospholipids with saturated fatty acid chain were preferred in most of liposome drug products, the major degradation pathway of phospholipids in liposome formulations are limited to hydrolysis of phospholipids into free fatty acids and lysophospholipids. These hydrolyzed degradation products may form during manufacturing and/or long-term storage of liposomal formulations. Herein, we report development and application of accurate and sensitive methods that can be utilized for the quantitation of saturated free fatty acids (FFA 18:0 and FFA 16:0), lysophosphocholines (LPC 18:0 and LPC 16:0), and lysophosphoglycerol (LPG 18:0) in liposomal formulations. The free fatty acids were separated using a C8 column whereas the LPCs and LPGs were separated using a C18 stationary phase upon direct injection without the need of lipid extraction process. Each analyte was quantified by Q-TOF mass spectrometry. This method was validated according to USP compendial procedures and has been applied to the analysis of four commercial liposomal pharmaceutical formulations. The limit of quantitation (LOQs) of FFA 16:0, FFA 18:0, LPC 16:0, LPC 18:0 and LPG 18:0 are 5 ng/mL, 5 ng/mL, 6.5 ng/mL, 7.0 ng/mL, 10 ng/mL respectively. Compared to CAD (Charge Aerosol Detector) and ELSD (Evaporative Light Scattering Detector) detection methods in ppm levels, this ultra-performance liquid chromatography (UPLC)-Mass Spectroscopy (MS) method displays precise determination of lysophospholipids in the liposomal formulations with higher accuracy and sensitivity.
鉴定和定量脂质体制剂中的辅料相关降解产物很重要，因为它们可能会影响药物的安全性和疗效。磷脂是构成脂质双层的脂质体药物的主要辅料之一，它们容易发生氧化和水解反应。由于大多数脂质体药物产品中都优先使用具有饱和脂肪酸链的磷脂，因此脂质体制剂中磷脂的主要降解途径仅限于磷脂水解成游离脂肪酸和溶血磷脂。这些水解降解产物可能在脂质体制剂的制造和/或长期储存过程中形成。在此，我们报告了开发和应用准确、灵敏的方法，可用于定量脂质体制剂中的饱和游离脂肪酸（FFA 18:0 和 FFA 16:0）、溶血磷脂酰胆碱（LPC 18:0 和 LPC 16:0）和溶血甘油磷脂（LPG 18:0）。游离脂肪酸采用 C8 柱分离，而 LPC 和 LPG 则采用 C18 固定相直接注入分离，无需进行脂质提取过程。每种分析物均通过 Q-TOF 质谱定量。该方法根据 USP 专论程序进行了验证，并已应用于四种商业脂质体药物制剂的分析。FFA 16:0、FFA 18:0、LPC 16:0、LPC 18:0 和 LPG 18:0 的定量限（LOQ）分别为 5ng/mL、5ng/mL、6.5ng/mL、7.0ng/mL 和 10ng/mL。与 CAD（电荷气溶胶检测器）和 ELSD（蒸发光散射检测器）检测方法相比，ppm 级别的该超高效液相色谱（UPLC）-质谱（MS）方法显示出对脂质体制剂中溶血磷脂具有更高的准确性和灵敏度的精确测定。
