Deformable liposomes as topical formulations containing alpha-tocopherol

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 41 to 201. The liposomes obtained were able to entrap alpha-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 alpha-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.