Analysis Methods And Pharmacokinetics Of Thymopentin

As an important immune regulator, the therapeutic efficacy of thymopentin (TP5) on many diseases has been reported. However, few were about the qualitative or quantitative determinations of TP5, in biopharmaceutical samples especially. The current study is about the methods for the analysis and its application on pharmacokinetic study of TP5. The discussion is divided into four parts as below.1) SDS-PAGE and gel filtration chromatography for the qualitative analysis of TP5: Sample bands of TP5 showed neither on two nor on three layers of SDS-PAGE gels, while the gel filtration chromatography was suitable for qualitative purpose with a retention time of 21 minutes for TP5.2) Ultraviolet spectrophotometry, fluorometry, high performance size exclusion chromatography and gel filtration chromatography for quantitative analysis of TP5: Four methods were all established and validated for the quantitative analysis of TP5, however, each had its own analytical ranges and disadvantages.3) Gel filtration chromatography and capillary electrophoresis (CE) for determination of blood-drug concentration of TP5: Gel filtration chromatography failed to separate TP5 from the sample serum even after the pre-treatment of serum samples using precipitation technique with salt or organic solvents, while CE was a suitable method to separate TP5 from the sample serum, and tris-phosphoric acid buffer with pH7.4 was better for mouse serum while phosphate buffer with pH3.0 was suitable for rabbit serum.4) CE in the pharmacokinetic study of TP5: The elimination half-life of TP5 obtained in mice were 94.4s and 109.7s, which were different from reported value of 30s for human. But CE is still recommended as one of the most suitable methods for further study of pharmacokinetics on TP5.This study has established several methods on qualitative and quantitative analysis of TP5 in samples obtained in vivo or in vitro.