Poly(acrylate-co-vinylacetate) adhesive patch for sustained dermal delivery of vitamin A

Abstract

An adhesive patch-type delivery system is suggested for sustained dermal application of vitamin A. Poly(acrylate-co-vinylacetate) was used as a pressure-sensitive adhesive. In vivo skin permeation of vitamin A from the patch was studied and compared with that of a conventional oil-in-water cream. The patch was found to enable to prolong the skin permeation of vitamin A, whereas the cream showed an initial burst skin absorption. The relative vitamin A bioavailability of the patch was about 76.9%, compared with that of the cream. Patches were less irritable to skin than the cream when the same amount of vitamin A was loaded. The lower skin irritancy might be due to the sustained release of vitamin A from the patch matrix. Silicon replica analysis was carried out as a clinical study to quantify the effects of the vitamin A patch on cutaneous relief. Repeated application of vitamin A-loaded patches onto crow's feet wrinkles for 12 weeks resulted in a reduction of the total surface area and the length of the wrinkles by up to 23% and 17%, respectively, without irritation.