Pharmacokinetics of urine and epigoitrin in rats

Objective To develop a simple,rapid and sensitive liquid chromatography-tandem mass spectrometry( LC-MS / MS) method for simultaneous determination of uridine and epigoitrin in rat serum,and to study the pharmaceutical characteristics of uridine and epigoitrin in rat by this method. Methods The chromatographic separation w as accomplished on Agela C8analytical column( 150 mm × 4. 6 mm,5 μm) at aflow rate of 1. 0 mL·min- 1w ith the mobile phase consisting of V( methanol) ∶ V( w ater) = 5∶ 95. The serum concentrations of uridine and epigoitrin w ere detected by multiple reaction monitoring after the rat w as given Radix Isatidis at 10 g·kg- 1. Results The linear concentration ranges of the calibration curves for uridine and epigoitrin w ere from 40. 0 to 10 000. 0 μg·L- 1and 4. 0 to 1 000. 0 μg·L- 1,respectively. The intra-and inter-day relative standard deviation across three validation runs over the entire concentration range w as less than 15%. The average recoveries and the matrix effects w ere betw een( 100 ± 15) % for both uridine and epigoitrin. After intragastric administration of Radix Isatidis,the ρmax of uridine w as increased to 2 times of baseline level of endogenous uridine. The ρmax,tmaxand t1 /2of epigoitrin w ere( 0. 61 ± 0. 08) mg·L- 1,( 2. 25 ±0. 61) h,( 3. 64 ±1. 47) h,respectively. Conclusions The method is proved to be highly sensitive and suitable for pharmacokinetic investigation of both uridine and epigoitrin.