Study on Pharmacokinetics of Melatonin Orally Disintegrating Tablets and Common Tablets in Beagle Dogs

OBJECTIVE To compare pharmacokinetic parameters of melatonin orally disintegrating tablets and common tablets in Beagle dogs. METHODS The plasma concentrations of melatonin in 6 Beagle dogs were determined by HPLC and the pharmacokinetic parameters were calculated with DAS software after a single dose of 6 mg melatonin common tablets or orally disintegrating tablets.RESULTS The pharmacokjinetic parameters of the orally disintegrating tablets and common tablets of melatonin were as follows:ρmax(52.2±23.0) and(37.8±22.7) μg·L-1,tmax(0.37±0.10)and(0.56±0.17)h,AUC0-6(45.52±32.39) and(43.46±29.42) μg·h·L-1,t1/2(1.05±0.76) and(1.13±0.52)h.The relative bioavailability F0-6 was(106.91±17.30)% and F0-∞was(107.62±16.71)%.CONCLUSION Compared with the common tablets,the orally disintegrating tablets showed faster absorption and higher peak concentration.The two preparations are not bioequivalent.