A rapid and simple approach using 1H NMR was developed for determination of liposomal encapsulation efficiency without the need for physical separation of entrapped and non-entrapped marker. Measurements were made using a marker (homocarnosine) with a pH-sensitive 1H chemical shift in the presence of a pH gradient across the phospholipid vesicle membrane, or by addition of the chemical shift reagent, thulium(III)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra-(methylene phosphonic acid sodium salt) (TmDOTP5-). The measured encapsulation efficiencies for the liposomal dispersions prepared from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) through extrusion using 50, 200 and 1000 nm polycarbonate membranes were found to be identical using the two different experimental approaches.

中文翻译：

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使用质子NMR光谱测定脂质体的包封效率。

开发了一种使用1H NMR的快速简便的方法来测定脂质体的包封效率，而无需物理分离包埋和未包埋的标记物。使用具有pH敏感性1H化学位移的标记物（高纯碱），在整个磷脂囊膜上存在pH梯度的情况下，或通过添加化学位移试剂reagent（III）-1,4,7， 10-四氮杂环十二烷-1,4,7,10-四-（亚甲基膦酸钠盐）（TmDOTP5-）。使用两种不同的实验方法，发现由1,2-二棕榈酰-sn-甘油-3-磷酸胆碱（DPPC）通过挤出使用50、200和1000 nm聚碳酸酯膜制备的脂质体分散体的包封效率是相同的。