Pharmacokinetic studies of ethylediaminetetraacetic acid (EDTA) in rats

A gas chromatographic assay of ethylenediaminetetraacetic acid (EDTA) in rat serum and urine has been developed. The procedure involves benzene extraction of the sample, and uses the internal standard technique for determining EDTA concentrations in biological samples. The pharmacokinetics of EDTA was investigated in rats after i.v. injection of 5 and 50 mg/kg or oral administration of 50 and 250 mg/kg. No significant dose-related differences were between the mean biological half-lives (ranging between 21.6 and 22.9 min). EDTA was extracted in rat urine within 24 h of either i.v. dose, and within 80 min of the 50 mg/kg and 3 h of the 250 mg/kg or oral doses. In the applications described the analytical limit of sensitivity is 0.5 microgram/ml of rat serum of urine.