A conjugate of prednisolone with albumin is pharmacologically active in macrophages.

In order to selectively deliver prednisolone to macrophages, this drug was coupled to human albumin. In experiments in vitro the conjugate entered into macrophages in much higher amounts than in fibroblasts; in the former cells it was pharmacologically active as demonstrated by the inhibition of prostaglandin E2 and thromboxane A2 production. Prednisolone-albumin conjugate might be useful in research on steroids; moreover in some pathological conditions it might produce the therapeutic effects of these drugs without causing their side effects.