Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Pharmacokinetics of enantiomers of oxiracetam in rats

Wu-San Wang¹ , Yu-Feng Wen²

¹Department of Pharmacology, College of Pharmacy; ²School of Laboratory Medicine, Wannan Medical College, Wuhu, Anhui Province 241002, China.

For correspondence:- Wu-San Wang Email: vq1277@163.com

Accepted: 27 November 2018 Published: 27 December 2018

Citation: Wang W, Wen Y. Pharmacokinetics of enantiomers of oxiracetam in rats. Trop J Pharm Res 2018; 17(12):2483-2487 doi: 10.4314/tjpr.v17i12.26

© 2018 The authors.
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Abstract

Purpose: To investigate the differences in pharmacokinetics of S-oxiracetam (S-ORT) and R-oxiracetam (R-ORT) in rats.

Methods: Sprague-Dawley rats (20) were randomly divided into two groups (ten rats per group), viz, S-ORT and R-ORT groups. Rats in S-ORT group received 200 mg S-ORT/kg while rats in R-ORT group were given 200 mg R-ORT/kg. Both treatments were given orally, and blood samples were collected at fixed time intervals for analysis. Ultra performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC–ESI-MS/MS) was used for pharmacokinetic analysis. Portions of the rat plasma were also subjected to configurational transformation analysis using normal phase-high performance liquid chromatographic (NP-HPLC) fitted with a Chiral OC column. Blank blood samples from five rats were used for plasma protein binding rate studying.

Results: The two enantiomers did not transform into each other after oral administration, and the concentrations of S-ORT at 1, 1.5 and 2 h were significantly higher than those of R-ORT (p < 0.05). The area under the curve (AUC_0-∞) and maximum concentration (C_max) of S-ORT were also significantly larger than those of R-ORT (p < 0.05). There were no stereoselective differences between the two enantiomers.

Conclusion: There are significant differences in absorption between two ORT enantiomers, and this may result in different pharmacological effects.

Keywords: S-oxiracetam, R-oxiracetam, Configuration, Pharmacokinetics, Rats