Advantan* is a new potent corticoid preparation that has been specially developed for the local treatment of eczematous dermatoses. The active ingredient of Advantan is methylprednisolone aceponate (MPA), a nonhalogenated corticoid diester. Advantan has been developed in three different formulations (cream, ointment, fatty ointment). Pharmacological studies have shown that the potency of MPA in the skin after dermal application is almost equivalent to that of Cvalerate and clobetasol propionate, and exceeds that of hydrocortisone butyrate. The toxicological programme provided no grounds for doubting the safety of products containing MPA, when used as directed. Like all other corticoids, MPA exerts its action via an intracellular receptor but its pharmacokinetic properties differ from those of other corticoids in that it leads to a high degree of dissociation between topical and systemic action. As a result of the two-fold esterification, MPA is highly lipophilic. Thus, it penetrates readily into the skin where it is hydrolysed forming 6α-methylprednisolone 17-propionate. For an understanding of the high local activity of MPA it is of importance to know that the product of the hydrolysis is a stronger corticoid than MPA. On absorption into the blood the metabolite is rapidly inactivated by conjugation with c acid, which explains the low systemic activity of MPA.