[Anti-inflammatory effects of methylprednisolone aceponate in animals]

In the case of dermal application of the drugs to croton oil-induced ear edema in rats and picryl chloride-induced delayed type hypersensitivity in mice, the anti-inflammatory effect of methylprednisolone aceponate (MPA) was slightly weaker than those of clobetasol 17-propionate and diflucortolone 21-valerate, but stronger than those of hydrocortisone 17-butyrate and hydrocortisone 17-butyrate 21-propionate. Betamethasone 17-valerate applied dermally was less and more effective than MPA to ear edema in rats and delayed type hypersensitivity in mice, respectively. The anti-inflammatory effect of MPA was weaker in subcutaneous administration than in topical application to the two inflammatory models. It was suggested that MPA has strong anti-inflammatory effects and weak systemic effects by topical application. Methylprednisolone 17-propionate (MP-17P) and methylprednisolone (MP), unesterified in only the C-21 position and in both the C-17 and 21 positions of MPA, respectively, showed weaker anti-inflammatory activities than MPA by topical application to croton oil-induced ear edema. The ratio of the anti-inflammatory effects by topical application to subcutaneous administration of MPA was higher than those of MP-17P and MP. The excellent characteristics of MPA as a dermal anti-inflammatory drug are suggested to be derived from di-esterification of MP, which has a weak activity intrinsically.