title: Increased bioavailability of hydrocortisone dissolved in a cream base.
abstract: OBJECTIVE
  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.
authors.affiliation: Ego Pharmaceuticals, Braeside, Victoria, Australia.
authors.forename: Kerryn A
authors.initials: KA
authors.lastname: Greive
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Barnes
mesh_terms: D000279:Administration, Cutaneous; D000893:Anti-Inflammatory Agents / Q000493:pharmacokinetics* / Q000494:pharmacology; D001682:Biological Availability; D004311:Double-Blind Method; D006801:Humans; D006854:Hydrocortisone / Q000493:pharmacokinetics* / Q000494:pharmacology; D010328:Patch Tests; D063465:Skin Cream / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects; D014870:Water Loss, Insensible / Q000187:drug effects
chemical_list: D000893:Anti-Inflammatory Agents; D006854:Hydrocortisone
keywords: bioavailability; blanching; moisturising; skin hydration; topical hydrocortisone; transepidermal water loss; vasoconstrictor assay; water content