Plasma 17-Hydroxycorticosteroid Concentrations in Fasted Dogs Following Oral Administration of Hydrocortisone Esters

Summary

Plasma 17-OHCS concentrations in the dog have been compared following oral administration of hydrocortisone, hydrocortisone cyclopentylpropionate, hydrocortisone acetate, hydrocortisone α-ethylbutyrate, and hydrocortisone α-ethylisovalerate. Prompt elevation of plasma 17-OHCS occurred within an hour after administration of any of these steroids. The magnitude of the response varied with the ester and dose but was always less than observed after an equivalent dose of hydrocortisone. At higher doses, the esters displayed a more prolonged elevation of plasma 17-OHCS than found after hydrocortisone. In this respect, hydrocortisone cyclopentylpropionate was superior to other preparations studied. It is concluded that esterification alters the rate of steroid absorption.