title: Plasma and skin concentration of 5-methoxypsoralen in psoriatic patients after oral administration.
abstract: The aim of this work was to investigate the distribution of 5-methoxypsoralen in the skin after oral administration of the drug and to examine the correlation between skin and plasma concentrations. 5-Methoxypsoralen skin concentration was measured in both healthy and psoriatic sites of 10 psoriatic patients after single and multiple oral doses. The results obtained show that 5-methoxypsoralen accumulates at higher levels in the more external layers of the skin after oral administration. The high affinity of drug for the stratum corneum was confirmed by in vitro skin affinity measurements. The concentration of 5-methoxypsoralen in the skin was similar in both psoriatic and healthy sites, indicating that the pathology does not influence drug distribution in the skin. After single dose administration, a linear correlation was found between skin and plasma drug concentration. After multiple dose administration, drug concentration in the skin was fairly constant despite the variable plasma concentrations in different subjects.
authors.affiliation: Institute of Dermatology, Faculty of Medicine, University of Parma, Parma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Zucchi
authors.forename: E
authors.initials: E
authors.lastname: Raho
authors.forename: B
authors.initials: B
authors.lastname: Marconi
authors.forename: S
authors.initials: S
authors.lastname: Nicoli
authors.forename: M
authors.initials: M
authors.lastname: Santini
authors.forename: F
authors.initials: F
authors.lastname: Allegra
authors.forename: P
authors.initials: P
authors.lastname: Colombo
authors.forename: R
authors.initials: R
authors.lastname: Bettini
authors.forename: P
authors.initials: P
authors.lastname: Santi
mesh_terms: D000078223:5-Methoxypsoralen; D000284:Administration, Oral; D000328:Adult; D020405:Dermis / Q000737:chemistry; D004817:Epidermis / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D008730:Methoxsalen / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics*; D008875:Middle Aged; D011701:PUVA Therapy; D011565:Psoriasis / Q000188:drug therapy*; D014018:Tissue Distribution
chemical_list: D000078223:5-Methoxypsoralen; D008730:Methoxsalen