Development of an In Vitro secondary transfer model for testosterone gel to elucidate protocols of safe contact.

Abstract

Testosterone gels applied to skin carry a risk of secondary transfer to non-patients , leading to development of symptoms such as precocious purberty. Currently, there is a lack of in vitro data available to inform guidance over safe contact parameters. A secondary transfer model using porcine skin to model primary (patient) skin and secondary (contact) skin was employed, with testosterone permeation and distribution analysis after 24 hours. Primary skin saw increasing amounts of unabsorbed testosterone and a reduction in delivery to the skin during at later contact times. Secondary skin saw a reduction in unabsorbed testosterone and delivery with later contact times. Permeation data mirrored the distribution data. These differences could be explained by changes in the formulation on the skin surface after application.