By spraying ¹⁴C-labeled α-tocopheryl acetate on the surface of the skin, and by conducting microradiographic investigations on the condition of its absorption in seven cases and 14 samples, the following observation have been acquired, and at the same time, some discussion have been made.
1. α-Tocopheryl acetate is absorbed well through the healthy hartless skin.
2. There are two routes of absorption from the surface of the skin to the dermis. The first one leads through the horny layer, the epidermis and the borderline between the epidermis and the dermis. The second one goes through the pilo-sebaceous canal, the interior of hair follicles, inner and outer root sheaths and connective-tissue sheaths. No route through the sebaceous gland and sweat ducts has been detected.
3. The material has proven to have a high affinity for small blood vessels everywhere.
4. Hesitation in the absorption of the material has been observed in line with the lower part of the horny layer, the borderline between the epidermis and dermis, the borderline of inner and outer root sheaths, and the borderline between epidermal and connective-tissue hair follicles.
5. Noticeable observations on the study of microdistribution are as follows:
(a) In a comparatively short period of time, a large quantity of the material has appeared in hair papillae.
(b) Although a large quantity of the material is seen in the sebaceous gland and excretory ducts, it is scarcely detected in the environment of those systems.
(c) The material has not been seen in the sweat gland and sweat ducts. However, a large quantity of the agent has been witnessed in the environment of these systems and also in the blood vessels around them.
(d) Although the agent has not been observed in the fatty cell, it was seen in the fatty intercellular septum in large quantities.