Human skin retention and penetration of a copper tripeptide in vitro as function of skin layer towards anti-inflammatory therapy

Abstract

Objective and design: The skin retention and penetration characteristics of copper applied as glycyl-L-histidyl-L-lysine cuprate diacetate were evaluated in vitro in order to assess the potential for its transdermal delivery as antiinflammatory agent. Materials and methods: Flow-through diffusion cells with 1 cm2 exposure area were used under infinite dose conditions. 0.68% aq. Copper as a tripeptide was applied on isolated stratum corneum, on heat-separated epidermis and on dermatomed skin. Receptor fluid collected over 48 h in 4 h intervals was analyzed by inductively coupled plasma mass spectrometry for copper in tissues and receptor fluid. Results The permeability coefficient of the compound through dermatomed skin was 2.43 ± 0.51 × 10-4 cm/h; 136.2 ± 17.5 μg/cm2 copper permeated 1 cm2 of that tissue over 48 h, while 82 ± 8.1 μg/cm2 of copper were retained there as depot. Conclusions: Applied tansdermally as the tripeptide on human skin ex vivo, copper permeated the skin and was also retained in skin tissue in amounts potentially effective for the treatment of inflammatory diseases. © The Author(s) 2010.