Pharmacokinetic study of melamine in rhesus monkey after a single oral administration of a tolerable daily intake dose

To perform pharmacokinetic study of melamine in rhesus monkey, melamine was orally administered to three experimental monkeys at a single dose of 1.4 mg/kg body weight. Plasma and urine were collected for the determination of melamine and cyanuric acid with a liquid chromatography tandem mass spectrometry method. The mean ± SD area under the concentration–time curve from time zero to 48 h (AUC0–t) was 14,145 ± 2002 μg/L h. The maximum concentration of melamine in plasma (Cmax) was 1767 ± 252 μg/L. The time to maximum concentration (Tmax) was 2.67 ± 1.16 h and the half-life of melamine in plasma (t1/2) was 4.41 ± 0.43 h. Following oral administration, melamine was rapidly excreted, mainly through urinary clearance. No significant correlation was found between melamine and cyanuric acid, suggesting that cyanuric acid may not be derived from melamine.