Biodistribution of 64Cu in rats after topical application of two lipophilic anti-inflammatory Cu(II) formulations.

64Cu(II) is extensively absorbed and excreted, mainly in the faeces, when applied to the skin of rats as complexes with (a) salicylate in ethanol with dimethylsulphoxide and glycerol or (b) phenylbutazone in dimethyl sulphoxide and glycerol, previously found to be anti-inflammatory. 64Cu distribution paralleled that observed after administering aqueous 64Cu-salicylate i.m. It is concluded that copper(II) can pass rapidly through the dermal barriers when applied with an appropriate cupriphore and presented in a medium with low water content.