Deformable Liposomes as Topical Formulations Containing α‐Tocopherol

Abstract

Several deformable liposomes were formulated using hydrogenated soya lecithin and sodium cholate, polisorbate 80, dipotassium glycyrrhizinate, or saccharose monopalmitate. The lipid:surfactant w/w ratio necessary to obtain elastic vesicles depended on the O/W surfactant and ranged from 4∶1 to 20∶1. The liposomes obtained were able to entrap α‐tocopherol and tocopheryl acetate up to 0.17% w/w.

Elastic liposomes, whose deformability was confirmed by filtration through microporous filters and differential scanning calorimetry measurements, when non‐occlusively applied on pig ear skin, determined negligible skin fluxes of α‐tocopherol, while skin deposition significantly increased compared with reference solutions or normal liposomes. Moreover, the entrapment of the vitamin either in elastic or in normal liposomes increased its photo‐stability under UVB irradiation.

Keywords:

• α‐Tocopherol
• deformable liposomes
• photo‐stability
• skin deposition