title: Ibuprofen transport into and through skin from topical formulations: in vitro-in vivo comparison.
abstract: The goal was to compare ibuprofen transport into and through skin in vivo in man and in vitro (across silicone membranes and freshly excised pig skin) from four marketed formulations. Ibuprofen gels were administered in vivo for 30 minutes. The stratum corneum (SC) at the application site was then tape-stripped, quantified gravimetrically, and extracted for drug analysis. Together with concomitant transepidermal water loss measurements, SC drug concentration-depth profiles were reproducibly determined and fitted mathematically to obtain a partition coefficient, a first-order rate constant related to ibuprofen diffusivity, and the total drug amount in the SC at the end of the application. All derived parameters were consistent across formulations. Ibuprofen permeation data through both silicone membrane and pig ear skin were also fitted to yield partitioning and diffusion parameters. The former revealed that ibuprofen partitioned differently from the gels into this model barrier. Across pig skin, however, better correlation with in vivo results was found. The dermatopharmacokinetic approach, using SC tape-stripping, offers a valid method to assess equivalency between topical drug formulations. In vitro experiments must be extrapolated cautiously to the clinic, especially when complex interactions between real formulations, which deliver both drug and excipients, and the skin occur.
authors.affiliation: School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Herkenne
authors.forename: Aarti
authors.initials: A
authors.lastname: Naik
authors.forename: Yogeshvar N
authors.initials: YN
authors.lastname: Kalia
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hadgraft
authors.forename: Richard H
authors.initials: RH
authors.lastname: Guy
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000818:Animals; D001692:Biological Transport; D001834:Body Water / Q000378:metabolism; D005260:Female; D006801:Humans; D007052:Ibuprofen / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D010539:Permeability; D012828:Silicones; D012867:Skin / Q000378:metabolism*; D013552:Swine
chemical_list: D008567:Membranes, Artificial; D012828:Silicones; D007052:Ibuprofen