Pharmacokinetics and bioavailability of sustained release melatonin tablets in healthy dogs by HPLC-MS

OBJECTIVE To compare data of pharmacokinetics and bioavailability between sustained release melatonin tablets and commercial tablets.METHODS A single oral dose of 6 mg test or reference preparations was given to 6 healthy dogs in a randomized crossover study. The serum concentrations of melatonin were determined by HPLC-MS method. RESULTS The pharmacokinetic parameters of two kinds of tablets were as Mows:tmax(2.08±0.20),(1.13±0.59) h;ρmax(4.66±6.87),(6.54±6.16)μg·L-1;AUC(13.21±17.21),(11.48± 5.37)μg·h·L-1.CONCLUSION The relative bioavailability of sustained release tablets is(87.79±72.68)% compared with the commercial tablets.The two formulations are bioequivalent.