Evaluation of human skin absorption risk for pharmaceutical and cosmetic products: an in-vitro approach
By Christelle Gélis, Eurofins ADME Bioanalyses, France
It has been widely recognised that the skin can be an important route of entry for industrial chemicals and pesticides. For this reason, data on skin absorption are often required for risk assessment purposes, and both animal models and in vitro systems are used to predict skin absorption in humans.
Skin absorption studies are carried out to determine the rate at which chemicals from pharmaceutical and cosmetic products are able to penetrate skin. The chemical dermal delivery rate is mainly of interest for regulatory agencies concerned with chemical exposures in the workplace. U.S. federal and European agencies that require the submission of skin absorption data include the Environmental Protection Agency, the Food and Drug Administration, the Occupational Safety and Health Administration and the Agency for Toxic Substances and Disease Registry.
In vitro model such as Franz cell was used with human skin coming from a surgical operation in order to evaluate the skin absorption. This approach is now accepted as a total replacement for animal-based skin absorption studies.
Absorption of a test chemical is measured over time by analysis of the receptor fluid (mimics the blood circulation) and the treated skin. The reliability and relevance of in vitro skin absorption studies have been thoroughly established through a number of international expert reviews, and these methods have been codified and accepted as an official test guideline of the Organisation for Economic Cooperation and Development (OECD).
The non-animal tests have a number of scientific advantages over the animal tests, including the ability to study a broader range of doses, including those at the actual level of exposure. This approach allows customers to make a decision regarding the absorption of a new drug or formulation modification and evaluate the risk for human beings. Eurofins Pharma Services designs studies that can be adapted in order to demonstrate the efficiency of a product in a specific layer of the skin and helps customer in drug candidate selection or development for topical route.
Contact: bioanalysis@eurofins.com
