“…9a-Fluorohydrocortisone.-The substitution of fluorine for hydrogen in the 9a-position of hydrocortisone increased the oral potency eight-to tenfold with respect to such parameters as eosinopenic and hyperglycemic potencies and ASTH-suppressing, nitrogen-wasting, and antiinflammatory activities (36,133,134). The topical anti-inflammatory action was increased also by a factor of 10 on the basis of studies by Witten (135), Robinson (136), and Lubowe (137), showing that 0.1% and 0.25% concentrations of 9a-fluorohydrocortisone 2 1-acetate were, in the majority of paired comparisons, equivalent in activity to 1.0% and 2.5y0 concentrations of hydrocortisone or hydrocortisone 2 1-acetate, respectively. None of these investigators observed any untoward systemic symptoms when the topical preparations were applied from two to four times daily for periods ranging from a few weeks to several months.…”