Cutaneous Permeation and Penetration of Sunscreens: Formulation Strategies and In Vitro Methods

The document reviewed in vitro studies on sunscreen permeation and retention, emphasizing the importance of formulation strategies to prevent systemic absorption and potential DNA damage. It discussed the effectiveness and stability of various UV filters, the impact of nanotechnology, and the use of three-dimensional human skin cultures as alternatives to animal testing. Techniques like encapsulation in lipid nanoparticles and bioadhesive nanoparticles were found to reduce skin penetration and enhance photoprotection. The review highlighted the need for standardized in vitro methods to predict in vivo performance and ensure regulatory compliance.