Absolute Bioavailability and Effect of Food on the Disposition of Safinamide Immediate Release Tablets in Healthy Adult Subjects.
The objectives of this study were to establish the basic intravenous (IV) single-dose PK of safinamide and its major human metabolites, the absolute bioavailability (BA) and food effect on safinamide tablets. Fourteen healthy adult male and female subjects received 50 mg safinamide single-dose treatments according to a randomized, 3-period, 2-sequence crossover design: immediate release (IR) tablets, administered after an overnight fast and after a standardized high-fat, high-calorie breakfast, and IV solution, administered over 30 minutes. Treatments were separated by wash-out intervals of at least 17 days. Serial blood samples were collected for 240 hours postdosing to evaluate safinamide parent drug and metabolite concentrations for the determination of PK parameters. The absolute BA of safinamide 50 mg IR tablets was high, with geoMean AUC0-∞ ratios of about 95% (90% CI: 90-99%) indicating that safinamide is virtually completely absorbed after oral administration. Safinamide IR tablets did not display a food effect on exposure parameters; both 90% CIs for the ratios fed/fasted of AUC0-∞ and Cmax were entirely within the bioequivalence acceptance margins of 80-125%. Only tmax was delayed by about 30% in the fed state. Oral and IV safinamide 50 mg single-dose administrations were generally well tolerated.
Department of Exploratory Medicine, Merck KGaA, Darmstadt, Germany.
Annick
A
Seithel-Keuth
Department of Exploratory Medicine, Merck KGaA, Darmstadt, Germany.
Andreas
A
Johne
Institute of Drug Metabolism and Pharmacokinetics, Merck KGaA, Grafing, Germany.
Achim
A
Freisleben
Department of Biostatistics, Merck KGaA, Darmstadt, Germany.
Katrin
K
Kupas
Nuvisan GmbH, Neu-Ulm, Germany.
Michael
M
Lissy
Department of Exploratory Medicine, Merck KGaA, Darmstadt, Germany.
Sonja
S
Krösser
absolute bioavailability; food effect; pharmacokinetics; safinamide