“…In these experiments, the skin is maintained between the donor and receptor diffusion chambers, and the permeation of a chemical from the donor chamber into and across the skin is measured. These skin permeation studies provide valuable information in risk assessment related to percutaneous absorption after skin exposure to hazardous chemicals (Flynn, 1990; Frasch et al, 2014), development of topical and transdermal formulations (Nicoli et al, 2006; Roy et al, 1996), evaluation and comparison of dermatological products (Bassani and Banov, 2016; Olivier et al, 2003), assessment of new topical and transdermal drug delivery technologies (Li et al, 2001; Tezel et al, 2004; Xu et al, 2009), and identification of the mechanisms of skin formulations such as permeation enhancers (Chantasart and Li, 2012; Charoenputtakun et al, 2015). These studies can also be used for quality control in product manufacturing (USP725, 2009) and bioequivalence assessment (FDA, 2016; Franz et al, 2009; Lehman and Franz, 2014).…”