title: Percutaneous penetration of 5-methoxypsoralen in rhesus monkeys.
abstract: OBJECTIVE
  5-methoxypsoralen (bergapten) has been used in the treatment of psoriasis and vitiligo, and as a sun tanning accelerator. While low plasma concentrations have previously been detected, there is no data on its dermatopharmacokinetics.
  
  
  METHODS
  Three rhesus monkeys were used as a model for human skin. [14C]-5-methoxypsoralen, as a parenteral excretion control, was injected in propylene glycol with an activity of 1.12 uCi/ml at a concentration of 80 mcg/ml and urine was collected at 4, 8, 12, 24h, and then daily for a total of 6 days. [14C]-5-methoxypsoralen was then applied topically in acetone with a dose of 1.19 mc (72 mcg) and urine was collected at 4 and 24h and then daily for a total of 7 days. The amount excreted was corrected for the previously determined parenteral excretion kinetics.
  
  
  RESULTS
  Intramuscular [14C]-5-methoxypsoralen had an average of 71.87±7.77% of excretion and percutaneously applied [14C]-5-methoxypsoralen had an average of 58.4±11.8% of excretion.
  
  
  CONCLUSIONS
  A high percentage of the administered 5-methoxypsoralen was absorbed. This provides a foundation of methodology to evaluate the efficacy of other delivery vehicles for 5-methoxypsoralen and serves as part of its dermatotoxic profile.
authors.affiliation: University of California, Department of Dermatology, 90 Medical Center Way, Surge 110, San Francisco, CA 94143-0989, USA.
authors.forename: Sailesh
authors.initials: S
authors.lastname: Konda
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000078223:5-Methoxypsoralen; D000279:Administration, Cutaneous; D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis; D007273:Injections, Intramuscular; D008253:Macaca mulatta; D008730:Methoxsalen / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000652:urine; D023421:Models, Animal; D010084:Oxidation-Reduction; D011565:Psoriasis / Q000188:drug therapy* / Q000378:metabolism; D012867:Skin / Q000473:pathology; D012869:Skin Absorption / Q000187:drug effects*; D014820:Vitiligo / Q000188:drug therapy* / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D000078223:5-Methoxypsoralen; D008730:Methoxsalen