Application of the Hill top Patch Test Chamber to Dermal Irritancy Testing in the Albino Rabbit

Abstract

AbstractA new occlusive patch test system employing a plastic chamber, the Hill Top Chamber (HTC), was evaluated as a method of application in rabbit dermal irritancy testing. Two commercial bar soaps were tested at 20%, 10%, 5%, 2.5%, and 1.25% concentrations in distilled water using both the HTC and the standard gauze patch methods of application. Each solution was applied to both intact and abraded skin sites on the dorsal flank, clipped free of hair, of six New Zealand albino rabbits (2.0–4.0 kg). The solutions were applied by gauze patch on one side of the animal and by HTC on the other side. The trunk of each animal was then wrapped with an impervious cover, which was left in place for 24 hr. After 24 hr, the wrap, patches, and chambers were removed. The application sites were scored for erythema and edema upon patch removal and again at 72 hr according to the standard Draize scale and the primary irritation index for each solution by both methods was calculated. The scores for both erythema and ede...