title: Skin absorption from patch test systems.
abstract: The development of topical drug products requires testing for skin toxicology reactions. A variety of patch test systems are available with which chemicals are applied to skin. The purpose of this study was to determine the skin absorption of paraphenylenediamine (PPDA) from a variety of such systems. [14C]-PPDA (1% pet., USP) was placed in a variety of patch test systems at a concentration normalized to equal surface area (2 mg/mm2). Skin absorption was determined in the guinea pig by urinary excretion of 14C. There was a six-fold difference in the range of skin absorption (p less than 0.02). In decreasing order, % skin absorption from the systems were Hill Top Chamber (53.4 +/- 20.6) greater than Teflon Control patch (48.6 +/- 9.3) greater than Small Finn Chamber with paper disc insert (34.1 +/- 19.8) greater than Small Finn Chamber (29.8 +/- 9.0) greater than Large Finn Chamber (23.1 +/- 7.3) greater than AL-Test Chamber (8.0 +/- 0.8). Thus, the choice of patch system could produce a false negative error if the system inhibits skin absorption, with a subsequent skin toxicology reaction.
authors: Department of Dermatology, University of California, San Francisco 94143.
authors: H O
authors: HO
authors: Kim
authors: R C
authors: RC
authors: Wester
authors: J A
authors: JA
authors: McMaster
authors: D A
authors: DA
authors: Bucks
authors: H I
authors: HI
authors: Maibach
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D006168:Guinea Pigs; D010328:Patch Tests / Q000379:methods*; D010655:Phenylenediamines / Q000493:pharmacokinetics* / Q000633:toxicity; D012869:Skin Absorption; D012882:Skin Tests / Q000379:methods*
chemical_list: D010655:Phenylenediamines; C029728:4-phenylenediamine