Capillary Bed Bioreactor: Improved Estimation Of Dermal Bioavailability

Historically, animal testing has been used to support risk assessment related to cosmetic ingredients. However, in recent years, there has been a continuous drive to reduce the level of animal testing undertaken to support risk assessments for new cosmetic products, and a move towards a mechanistic understanding of human toxicology (incorporating exposure-based risk assessment). Consequently, the development of non-animal models for predicting the safety of new chemicals is necessary to generate data leading to increased confidence in predictions of in vivo scenarios. The model used by Unilever to assess dermal bioavailability utilises skin (from elective cosmetic surgery procedures) in diffusion cells, and the permeation of a test item through the skin is monitored over time. While this has proved to be an adequate model, little is known regarding chemical clearance via dermal capillaries. The proposed capillary bed bioreactor (CBB) better replicates the in vivo environment of the skin and its blood supply by providing a bed of pseudovascularisation in the form of hollow fibre membranes.