title: Pharmacokinetic profiles in rats after intravenous, oral, or dermal administration of dapsone.
abstract: Dapsone is a potent anti-inflammatory and antibacterial agent that has been used extensively in the oral treatment of leprosy and dermatitis herpetiformis. This study compared the pharmacokinetic profile of dapsone in rats given a single oral or i.v. 12 mg/kg dose (n = 8/group) or a single dermal application of 12 or 60 mg/kg (n = 12/group) in an aqueous gel application medium containing 10 or 25% diethylene glycol monoethyl ether (DGME). Blood samples (200 microl) were collected via tail vein from each rat and pooled at intervals up to the 24-h period. A terminal blood sample was collected by cardiac puncture from each animal. Plasma concentrations of dapsone were determined by liquid chromatography atmospheric pressure ionization tandem mass spectroscopy. There was no treatment-related overt toxicity observed in any of the animals. Peak levels were reached 1 h after oral dosing (4890 ng/ml), and 6 to 8 h after dermal application, with Cmax values of 1.62, 5.56, and 12.8 ng/ml, for 12 mg/kg at 10 or 25% DGME, and for 60 mg/kg at 25% DGME, respectively. Bioavailability was calculated at 78% after oral dosing and <1% after dermal application. Apparent elimination half-lives (t(1/2))s were similar after i.v. and oral dosing. Both the calculated area under the plasma concentration versus time curve up to 24 h and Cmax values were 3- to 4-fold higher in the dermal application group administered 12 mg/kg dapsone in 25 versus 10% DGME gel, whereas the calculated area under the plasma concentration versus time curve up to 24 h and Cmax values for the 60 mg/kg group were only 3.3- and 2.3-fold greater than those obtained after application of 12 mg/kg in 25% DGME. These results show that both systemic exposure and peak plasma concentrations of dapsone are minimized by dermal versus oral administration of the compound.
authors.affiliation: Biological Test Center, Irvine, California, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Helton
authors.forename: D W
authors.initials: DW
authors.lastname: Osborne
authors.forename: S K
authors.initials: SK
authors.lastname: Pierson
authors.forename: M H
authors.initials: MH
authors.lastname: Buonarati
authors.forename: R A
authors.initials: RA
authors.lastname: Bethem
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D003622:Dapsone / Q000097:blood / Q000493:pharmacokinetics*; D007262:Infusions, Intravenous; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D003622:Dapsone