SKIN PERMEATION OF RETINYL PALMITATE FROM VESICLES

The delivery of retinyl palmitate (RP) from several vehicles, includin g those containing nonionic surfactant vesicles (NSV), was investigate d in vitro. Both excised hairless mouse and human skin were utilized a s model membranes in permeation experiments. intact retinyl palmitate was not detected in the receptor. Following application of various NSV preparations to hairless mouse skin, the label accumulated in the rec eptor at a rate comparable to or greater than from mineral oil. The op posite occurred with excised human skin. penetration into the receptor from a vesicle preparation, mineral oil and alcohol, was commensurate with accumulation in viable human skin tissue. Most of the label resi ding within human skin following application of the NSV preparation wa s found in the stratum corneum, to an extent significantly greater tha n for either of the other vehicles. We conclude that because of the im portance of storage in the stratum corneum, hairless mouse skin is not a good model for RP permeation. Also, vesicle preparations augment re tention of hydrophobic substances in stratum corneum with potential fo r extended effect.