title: In vivo percutaneous absorption of hydrocortisone: multiple-application dosing in man.
abstract: Percutaneous absorption of hydrocortisone was measured in six healthy adult men from whom informed consent had been obtained. The study compared a single topical dose to multiple-topical dose treatments (one vs three applications) on the same day. 14C-Labeled hydrocortisone in acetone was applied to 2.5 cm2 of ventral forearm skin and protected with a nonocclusive polypropylene chamber. The amount of 14C measured in urine collected over 7 days was used to determine hydrocortisone absorption. The treatments, performed 2 to 3 weeks apart, each utilized adjacent sites on the same individuals. A single dose of 13.33 micrograms/cm2 delivered 0.056 microgram/cm2 of hydrocortisone through the skin. When the single dose was tripled to 40 micrograms/cm2, the amount delivered through the skin increased by nearly three times, from 0.056 to 0.140 micrograms/cm2; the expected delivery was 3 x 0.056 micrograms/cm2 = 0.168 microgram/cm2. Three serial doses of 13.33 micrograms/cm2 (total, 40 micrograms/cm2) were also expected to deliver 0.168 micrograms/cm2 with or without soap and water washing between doses, but the observed amount of hydrocortisone delivered through the skin significantly exceeded our expectations. This indicates that multiple-dosing treatments resulted in a significant increase in bioavailability. It is postulated that increased vehicle application and washing dissolved and mobilized previously dosed hydrocortisone and increased bioavailability.
authors.affiliation: University of California School of Medicine, Department of Dermatology, San Francisco 94143-0989.
authors.forename: J L
authors.initials: JL
authors.lastname: Melendres
authors.forename: D A
authors.initials: DA
authors.lastname: Bucks
authors.forename: E
authors.initials: E
authors.lastname: Camel
authors.forename: R C
authors.initials: RC
authors.lastname: Wester
authors.forename: H I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000279:Administration, Cutaneous; D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006854:Hydrocortisone; D008297:Male; D008875:Middle Aged; D012869:Skin Absorption
chemical_list: D000893:Anti-Inflammatory Agents; D006854:Hydrocortisone