A simple method for assessing the percutaneous absorption of steroid preparations is suggested.
Using vasoconstriction as an index of absorption, occlusion of the skin surface with Saran Wrap results in a 100-fold difference in absorption over simple topical application.
McKENZIE AW, STOUGHTON RB. Method for Comparing Percutaneous Absorption of Steroids. Arch Dermatol. 1962;86(5):608-610. doi:10.1001/archderm.1962.01590110044005