Local antiinflammatory activity of acid ester derivatives of prednisolone.

The antiinflammatory activity of two steroid acid esters, methyl prednisolonate and methyl 20-dihydroprednisolonate, synthesized by modifying the 17 beta ketol side chain of prednisolone has been investigated in the cotton pellet granuloma bioassay in rats. The inhibitory effect of the ester derivatives on granuloma formation was equivalent to that of the parent compound. At dose of 5 mg/cotton pellet, methyl prednisolonate exhibited a highly significant thymolytic effect comparable to that of prednisolone, while methyl 20-dihydroprednisolonate had a weaker thymolytic effect. However, the local antiinflammatory activity of the two esters was not accompanied by a decrease in adrenal weight observed with the parent compound.