Optimization of the colloidal properties of different vesicular systems aiming to encapsulate (-)-epigallocatechin-3-gallate

Abstract

The objective of this study was to optimize different vesicular systems containing (-)-epigallocatechin-3-gallate (EGCG); namely penetration enhancer-containing vesicles, ethosomes, transfersomes and transethosomes in order to maximize its therapeutic efficacy. Empty vesicles were prepared using Epikuron 200 and permeation enhancers including polyethylene glycol 400, ethanol, Tween 80 and ethanol/Tween 80 mixture. The colloidal properties of the prepared vesicles were evaluated. Empty vesicles displaying optimum properties were selected for drug loading in order to evaluate their entrapment efficiency. Further optimization of the properties of the drug-loaded vesicles was performed through modification of the conditions of the encapsulation process. Results revealed that decreasing the amount of Epikuron 200 with increasing the percentage of the enhancer reduced the vesicles size and polydispersity index. Loading of vesicles with EGCG markedly increased their size and surface charge. Doubling the volume of hydration medium significantly reduced the size of drug-loaded vesicles while preserving the optimum encapsulation efficiency. Hence, it can be concluded that proper optimization of vesicular properties is necessary in order to maximize the entrapment and consequently the topical therapeutic potential of EGCG.