title: Methods for in vitro skin absorption studies of a lipophilic toxin produced by red tide.
abstract: The penetration and distribution of [3H]PbTx-3 into pig skin was determined using in vivo and in vitro methods. The dose used in each topical study was 0.3-0.4 micrograms/cm2 skin, with dimethylsulfoxide as the vehicle. In the in vivo study, mean cutaneous absorption after 48 h (expressed as percentage of the dose) was 11.5% (n = 3). In the in vitro study, mean cutaneous absorption after 48 h was 1.6% (n = 12), when based on accumulation of radioactivity in receptor fluid, or 9.9% when based on receptor fluid and dermis. [3H]PbTx-3 readily penetrated through the epidermis into the dermis, reaching maximal dermal accumulation at 4 h (9.1% in vivo and 18% in vitro). At 24 h, the amount in the dermis decreased to 2.3% and 15% in vivo and in vitro, respectively and at 48 h the amount in the dermis decreased to 8.2% in vitro. These results demonstrate the important role of the dermis as a reservoir for a lipophilic compound in both in vivo and in vitro percutaneous absorption studies.
authors.affiliation: Department of Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, AL 36849.
authors.forename: B W
authors.initials: BW
authors.lastname: Kemppainen
authors.forename: W G
authors.initials: WG
authors.lastname: Reifenrath
authors.forename: R G
authors.initials: RG
authors.lastname: Stafford
authors.forename: M
authors.initials: M
authors.lastname: Mehta
mesh_terms: D000287:Administration, Topical; D000818:Animals; D005260:Female; D008297:Male; D008387:Marine Toxins / Q000493:pharmacokinetics*; D035964:Oxocins; D012869:Skin Absorption; D013045:Species Specificity; D013552:Swine; D014018:Tissue Distribution; D014316:Tritium; D000095702:Polyether Toxins
chemical_list: D008387:Marine Toxins; D035964:Oxocins; D014316:Tritium; C041017:brevetoxin T17; D000095702:Polyether Toxins; C053342:brevetoxin