Penetration and Local Effect of Vitamin A on the Skin of the Guinea Pig.,

Vitamin A dissolved in alcohol or chloroform penetrates the intact skin quickly by way of the sebaceous glands. Dissolved in linoleic or oleic acid, or in a viscous petrolatum paste, it penetrates more slowly. Vit. A dissolved in oleic or linoleic acid or in alcohol causes an hypertrophy of the epidermis, but a similar hypertrophy is brought about by the fatty acids alone. Whereas the fatty acids, with or without vit. A, seem to retard keratinization slightly, the vitamin dissolved in alcohol does not. Hair growth was unimpaired even when the skin had received massive doses of vit. A dissolved in alcohol.