Assessment of the distribution of radiolabelled non-ionic multilamellar surfactant microvesicles following topical application to canine skin biopsies: a preliminary study

Abstract

Non-ionic multilamellar surfactant vesicles (Spherulites) represent a new generation of active ingredient carriers used for the development of topical products. This study aimed to assess the distribution of non-ionic Spherulites into canine skin. A suspension of Spherulites labelled with encapsulated 14C-palmitic acid was applied to the epidermis of cutaneous biopsies. Control biopsies were treated with non-encapsulated probe or left untreated. The distribution of radioactivity was assessed in cryostat sections by autoradiography and by direct radioactive imaging. Examination of sections showed that signals from the non-encapsulated probe were present at the skin surface. The distribution of radioactivity from the encapsulated probe (in non-ionic Spherulites) showed signals in the living epidermis, in hair follicles and in the dermis. This study suggests that non-ionic Spherulites are able to penetrate deeply into the skin of the dog.