Why hydrocortisone or hydrocortisone acetate in a cream?

The general rule is that the esters of corticosteroids are a better form for dermal application of the cortico-alcohol. Here are some values for hydrocortisone and ester derivatives: P = permeabilieitscoefficient by isolated skin and PC the distribution coefficient between ether and water, which is a measure of lipoophilism.                                                               P (CM/h)               PC hydrocortisone                                     1.6 x 10 -4             1.4   hydrocortisone-21-acetate                 1.7 x 10-3             27   hydrocortisone-21-propionate             9.8   x   10-3         95   hydrocortisone-21-butyrate                 4.3 x 10-2           300   You see that the strongest derivative is the butyrate ester, which is found in Locoid Crelo.   I do not exclude that provided that a special formulation of the excipient also hydrocortisone is absorbed. After all, the cutaneous absorption is a complex mechanism in which many parameters play a role.   but generally, hydrocortisone is reserved for oral intake (see TMF).