Percutaneous absorption of organic sunscreens.

The increased awareness of protection against skin cancer has led to a rise in the use of topically applied chemical sunscreen agents. There is a concern about the systemic absorption of organic filters in sunscreen formulations. The present study briefly reviews theoretical models for the prediction of the percutaneous penetration of the organic molecules and the accepted methods for the in vitro and in vivo evaluations of the penetration. The influence of the vehicle and the formulation viscosity on the penetration of sunscreens are examined. The development of novel methods for the minimization of sunscreen absorption is also discussed.