Human skin penetration of a copper tripeptide in vitro as a function of skin layer.

Abstract

Objective and designSkin retention and penetration by copper applied as glycyl-l-histidyl-l-lysine cuprate diacetate was evaluated in vitro in order to assess its potential for its transdermal delivery as an anti-inflammatory agent.Materials and methodsFlow-through diffusion cells with 1 cm2 exposure area were used under infinite dose conditions. 0.68% aq. copper tripeptide as permeant was applied on isolated stratum corneum, heat-separated epidermis and dermatomed skin and receptor fluid collected over 48 h in 4 h intervals using inductively coupled plasma mass spectrometry to analyze for copper in tissues and receptor fluid.ResultsThe 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 97 ± 6.6 μg/cm2 were retained as depot.ConclusionsCopper as tripeptide was delivered in potentially therapeutically effective amounts for inflammatory disease.