Increased bioavailability of hydrocortisone dissolved in a cream base.

ABSTRACT

BACKGROUND/OBJECTIVES: The aim of this study was to compare vasoconstrictor activity and, by inference, the clinical anti-inflammatory effectiveness of hydrocortisone in two different formulations 1% dissolved hydrocortisone cream and 1% dispersed hydrocortisone cream. Moisturising capacity and safety were also determined. METHODS: Both topical preparations were applied without occlusion on forearms twice daily for 5 days. An assessment of vasoconstriction was performed in a double-blinded manner pretreatment and then thrice daily for 6 days and once 7 days post-application, using an objective rating scale. For the dissolved preparation only, moisturising capacity was determined by measurement of transepidermal water loss (TEWL) at 0, 2, 4, 6 and 24 h, and also by the measurement of water content at 0 and 24 h. Safety was assessed by repeat insult patch tests (RIPT). RESULTS: In all, 10 volunteers completed the vasoconstrictor and moisturising studies, while 52 completed the RIPT. For 1% dissolved hydrocortisone cream and 1% dispersed hydrocortisone cream, respectively, areas under the blanching curves were 1240 and 295; total scores were 129.0 and 31.5; summed % total possible scores were 161.3 and 39.4; Tm/10 mean values were 3.47 and 1.64. The 1% dissolved hydrocortisone cream was found to be statistically more potent than the 1% dispersed hydrocortisone cream. Furthermore, the 1% dissolved hydrocortisone cream was found to be moisturising compared to no treatment. No adverse events were observed. CONCLUSIONS: A cream containing 1% dissolved hydrocortisone exhibits greater vasoconstrictor activity than a cream containing 1% dispersed hydrocortisone.