Hydrocortisone/Carbamide

Four commercially available topical preparations of cortisol, Alphaderm, Calmurid HC, Efcortelan and Topisone, had trace quantities of tritiated cortisol added to them. The resultant radiolabelled creams were applied to the dorsum of the pig and the penetration of the steroid was assessed. Alphaderm was shown to deliver approximately 16.0 times more cortisol to the skin than Topisone, approximately 8.0 times more than Efcortelan and approximately 3.0 times more than Calmurid HC.

The bio-availabilities and activities of commercial creams (Metosyn, Synalar, Betnovate, Locoid, Alphaderm, Dioderm and Efcortelan 1%) were assessed using a multiple dosage regimen vasoconstrictor assay in ten volunteers. The blanching response first increased but then diminished with continued application over a 5-day period: following a 2-day 'resting period', when no steroid was applied, the application sites recovered considerably but tachyphylaxis again resulted from subsequent repeated applications. Acute tolerance occurred with the hydrocortisone formulations (Alphaderm, Dioderm and Efcortelan 1%) in a manner similar to that observed with the potent preparations. Metosyn was significantly more active (P less than 0.05), and Efcortelan 1% was significantly less active (P less than 0.05), than the other formulations. Apart from the reversal of Dioderm and Alphaderm the rank order of preparations was similar to that previously noted in the 6 h occluded single-application vasoconstrictor test. The results may have significance in dosage from design and application for topical corticosteroid formulations.