Arkansas Laboratory, Office of Regulatory Science, Office of Regulatory Affairs, US Food and Drug Administration, Jefferson, AR 72079, United States.
Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD 20993, United States.
Int J Pharm. 2019 Oct 5;569:118603. doi: 10.1016/j.ijpharm.2019.118603. Epub 2019 Aug 8.
Conventional quantitation of drug content in the liposome formulation involves the breakdown of bulk liposomes, which ignores details on the distribution of the active pharmaceutical ingredient (API) and excipients in liposomes of different sizes. The objective of this study is to develop an analytical method which can separate the liposomes into different sizes and obtain information of the drug and excipient distribution in the different sized liposomes. We developed an asymmetric flow field-flow fractionation (AF4) method for size-based separation of AmBisome, an amphotericin B liposomal formulation, and a high-performance liquid chromatography ultraviolet-visible and charged aerosol detection (HPLC-UV-CAD) method for simultaneous quantitation of the API (Amphotericin B) and the lipid excipients [1,2-Distearoyl-sn-glycero-3-phosphoglycerol (DSPG), hydrogenated soy phosphatidylcholine (HSPC), and cholesterol]. The measured drug content in the bulk liposome formulation was consistent with the drug product labeling. Liposomes were separated using AF4 into eleven size fractions and the liposomes particles sizes of each fraction were measured with nanoparticle tracking analysis. The drug to total lipid ratios in fractionated liposomes increased from 0.1 to 0.45 when the liposome size increased from 75 nm to 124 nm, while the lipid composition remained constant throughout the fractioned size range (cholesterol:DSPG, 0.7 and HSPC:DSPG, 0.3). These study results suggest that, for liposomal formulations of Amphotericin B in liposomes, the drug to lipid ratio increases with the size of the liposomes. This new analytical method provided a more in-depth characterization of liposomes, i.e., determining drug and excipient distributions in different sizes of liposomes, in a more efficient manner with more specific size-based composition information.
传统的脂质体制剂中药物含量的定量分析涉及到对大量脂质体的破坏，这忽略了不同大小的脂质体中活性药物成分（API）和赋形剂的分布细节。本研究的目的是开发一种分析方法，可以将脂质体分离成不同的大小，并获得不同大小的脂质体中药物和赋形剂分布的信息。我们开发了一种不对称流场流分离（AF4）方法，用于分离两性霉素 B 脂质体制剂 AmBisome，并建立了高效液相色谱紫外可见光和带电气溶胶检测（HPLC-UV-CAD）方法，用于同时定量分析 API（两性霉素 B）和脂质赋形剂[1,2-二硬脂酰-sn-甘油-3-磷酸甘油（DSPG）、氢化大豆卵磷脂（HSPC）和胆固醇]。 bulk liposome formulation 中的实测药物含量与药品标签一致。使用 AF4 将脂质体分离成十一个粒径级分，并使用纳米颗粒跟踪分析测量每个级分的脂质体粒径。当脂质体粒径从 75nm 增加到 124nm 时，分级脂质体中的药物与总脂质的比例从 0.1 增加到 0.45，而脂质组成在整个分级粒径范围内保持不变（胆固醇：DSPG，0.7 和 HSPC：DSPG，0.3）。这些研究结果表明，对于两性霉素 B 脂质体中的脂质体制剂，药物与脂质的比例随脂质体的大小而增加。这种新的分析方法以更高效的方式提供了对脂质体的更深入表征，即更具体的基于粒径的组成信息，确定不同大小的脂质体中的药物和赋形剂分布。
