title: Transdermal drug pharmacokinetics in man: Interindividual variability and partial prediction.
abstract: A database of human dermatopharmacokinetic parameters of 12 transdermal patches is established. The effect of system design, application site, and metabolism on pharmacokinetic data is discussed, and interindividual variability of data and its possible sources evaluated. Using multiple regression analysis, two equations based on drugs physicochemical characteristics are suggested for partial prediction of peak plasma concentration (C(max)) after patch application. Patch application presumably decreases variance as rub-off, wash and exfoliation steps are diminished. The results showed that interindividual variation, in terms of coefficient of variation (CV) of C(max), is inversely correlated with drugs molecular weight and lipophilicity in the range of 200<MW<400 and 1.6<logK(oct)<4.3. Multiple regression analysis of C(max) against physichochemical parameters demonstrated the prominent contribution of hydrogen bonding acceptability of the molecules on their maximal plasma concentration after patch administration. The findings suggest that the serum concentration profile for transdermal therapeutic systems (TTS) is a net result of the system performance, drug absorption and elimination. Thus, the variability in serum concentration is a function of variability of each process involved. This should be noted in explanation of effect of molecular features of drugs on their plasma concentration profile.
authors.affiliation: Department of Dermatology, School of Medicine, University of California, San Francisco, 90 Medical Center Way, Surge 110, Box 0989, San Francisco, CA 941143-0989, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Farahmand
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000279:Administration, Cutaneous; D001682:Biological Availability; D004305:Dose-Response Relationship, Drug; D006801:Humans; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000097:blood*; D010599:Pharmacokinetics; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012869:Skin Absorption; D013810:Therapeutic Equivalency
chemical_list: D004364:Pharmaceutical Preparations