Research on an effective, accurate, and universally applicable method for dual-loaded liposomes encapsulation efficiency.

Abstract

Objective: Dual-loaded liposomes have become increasingly popular in the field of liposomal research. The encapsulation rate of dual-loaded drugs is an important indicator of the quality and efficacy of the dual-loaded liposomes. But it is difficult to determine the encapsulation efficiency of two drugs using a single method when the physicochemical properties of the drugs differ significantly. The aim of this study is to identify a method that is suitable for the different physicochemical properties of drugs and that efficiently and accurately determines the encapsulation efficiency of the two drugs in dual-loaded liposomes.

Methods: This study uses three different types of dual-loaded liposomes that simultaneously encapsulate lipophilic and hydrophilic drugs to examine the separation efficiency, encapsulation rate error, and applicability of various currently available methods for determining the encapsulation efficiency of dual-loaded liposomes. These methods include centrifugation, dialysis, ultrafiltration, microcolumn centrifugation, nanoparticle exclusion chromatography (nPEC), and polyethylene glycol-single-chain variable fragment (PEG-scFv) induced sedimentation.

Results: The results indicate that microcolumn centrifugation, nPEC, and PEG-scFv induced sedimentation methods achieved more than 90% separation efficiency for both lipophilic and hydrophilic drugs. Among these, microcolumn centrifugation is cumbersome to operate, and the PEG-scFv induced sedimentation method is only applicable to PEGylated liposomes. In contrast, the nPEC method requires no pre-treatment and is suitable for the separation of all nanoparticles and free drugs.

Conclusions: This study concludes through a comparative analysis that the nPEC method is an effective, accurate, and universally applicable method for assessing the encapsulation efficiency of dual-loaded liposomes.