Effect of crystal form onin vivo topical anti-inflammatory activity of corticosteroids

The aim of this study was to gain information on the effects of the crystal form of corticosteroids on the topical anti-inflammatory activity. Two different crystal forms, Form A and Form B, of the drugs of prednicarbate, hydrocortisone, betamethasone 17-valerate, prednisolone, and methyl prednisolone were prepared and their topical anti-inflammatory activities were measured using arachidonic acid induced ear edema assay in mice. Two crystal forms of the drugs showed differences in anti-inflammatory activity. Among the drugs examined, Form B of prednicarbate and betamethasone 17-valerate showed significantly more potent anti-inflammatory activities as compared to their Form A.