In vitro Skin Absorption and Dermal Penetration Test
1. Turnaround time: 8 weeks
The assessment of percutaneous permeation of molecules is important for many products, such as dermal or transdermal delivery systems (pharmaceuticals, cosmetics), agrochemicals (pesticides, herbicides or fungicides). In vivo assessment for cosmetic products is not allowed in the EC since 2013 according to EU Cosmetic Regulation 1223/2009. For cosmetic compounds and drugs in the early phases of development alternative models have been developed, such as ex vivo human skin, usually obtained from plastic surgery patients, ex vivo animal skin or mucosa’s from slaughterhouse. The ex vivo skins and mucosa’s are used for in vitro dermal absorption or penetration studies according to OECD 428 (2004a + 2004b), OECD GD 428 (2004c), WHO/IPCS (WHO 2006). The assessment of percutaneous absorption or skin permeation is important for the successful development of new formulations intended for human use. The absorption model with animal buccal mucosa has become an attractive model for studies of local and systemic drug delivery. Bovine nail sheets models have been developed for studies on nails.
The Franz Diffusion Cells include an ex vivo human or animal skin and imitates the behavior of chemicals, cosmetics, pharmaceuticals when applied to skin. Ex vivo skin discs are fixed in glass Franz Diffusion Cells between acceptor and receptor compartment and the test item is added above the skin disc, membrane respectively. The rate of transfer is determined by collection of the permeate in the sampling device of the Franz Cell. Usually, a phosphate buffer is added as a receiving solution. The liquid in the receptor cells is analyzed by HPLC. Franz Cells can be jacketed with controlled temperature water flow.
The test can be used to check the possibility of penetration of a medical device or its extract into the skin, which can be useful in classifying a medical device according to regulation 2017/745 (MDR).