Comparative single-dose pharmacokinetics of rasagiline in minipigs after oral dosing or transdermal administration via a newly developed patch.

1. A rasagiline transdermal patch was developed for the treatment of early and advanced Parkinson's disease. Relevant pharmacokinetic parameters of rasagiline obtained after transdermal administration to minipigs were compared with those of rasagiline after oral administration. 2. A total of 18 minipigs were randomly divided into three groups (six animals for each group). A single dose of 1 mg rasagiline tablet was orally administrated to one group. Meanwhile, single dose of 1.25 and 2.5 mg (2 and 4 cm(2)) rasagiline patches were given (at the postauricular skin) to the other two groups, respectively. The pharmacokinetic parameters such as plasma half-life (t1/2), time to peak plasma-concentration (Tmax), mean residence time (MRT), area under the curve (AUC(0-t)) were significantly (p < 0.05) different between transdermal and oral administrations. 3. The plasma half-life (t1/2) of rasagiline (1.25 mg patch: 11.8 ± 6.5 h, 2.5 mg patch: 12.5 ± 4.7 h) in minipig following transdermal administration was significantly prolonged as compared with that following the oral administration (1 mg tablet: 4.7 ± 2.5 h). The dose-normalized relative bioavailability of rasagiline patch in minipig were 178.5% and 156.4%, respectively, for 1.25 and 2.5 mg patches compared with 1 mg rasagiline tablet. The prolonged t1/2 and increased bioavailability of rasagiline patch suggested a possible longer dosing interval compared with oral tablet.