血浆半衰期

PTU的血浆半衰期仅1-2小时，抗甲状腺作用维持不到24小时，故需每日用药三次。

The plasma half-life of PTU is only 1-2h and its antithyroid function maintains less than 24h . So it has to be dosed three times a day .

异钩藤碱在大鼠组织中的分布及其血浆半衰期的测定

The distribution of isorhynchophylline in the tissues of the rats and the determination of its plasma half-life time

血浆半衰期相对较长，大多为3～7小时以上；

Serous half-life is relatively longer , it is3 ~ 7 hours mostly above ;

目的：用比色法测定水杨酸钠的光密度值，并计算血浆半衰期。

Objective : To determine the numerical value of light dense of sodium salicylate by colorimetric analysis , and calculate its plasma half life .

脂质体包封药物可以延长药物的血浆半衰期，提高血药浓度，增加疗效，减小药物的毒副作用。

Drug envelopment of liposome can extend plasma half-life of drugs , elevate blood drug level , increases therapeutic effect , diminish baneful adverse reaction .

与传统的肝素相比，低分子肝素具有抗血栓作用强、出血副作用小、生物利用度高、血浆半衰期长等优点，在国际市场上已开始逐渐取代肝素。

Compared with traditional heparin , low molecular weight heparin has a strong antithrombotic effect and a lower bleeding side effect , higher bioavailability , longer plasma half-life , etc. , and it seems that it can replace heparin in the international market .

麻醉和手术对实验动物血浆药物半衰期的影响

Effects of anesthesia and surgery on the half-life of plasma sodium salicylic in laboratory animals

所以分子量大于3万，且为中性电荷的聚合物在血浆内半衰期长。

As a result , a polymer with a appropriate Mw as well as a neutral charge can possess a long half-life in plasma .

然而，这类药物存在脂溶性差、在血浆中半衰期短、有各种毒副作用等缺点。研究表明，其经酰化修饰所得的酯类衍生物前药能有效地解决上述问题。

However , this class of drugs suffers from poor lipophilicity , short half-lives in human plasma and various side effects , etc. It has been reported that their ester prodrugs via the regioselective acylation can effectively overcome the aforementioned problems .

结论：低分子肝素具有高比例的抗因子Xa和抗因子Ⅱa活性，由于其分子量小，与血浆蛋白和内皮细胞结合减少，所以生物利用度高，血浆半衰期长。

Conclusion : Low-molecular-weight heparin may have specific anti-Xa and anti - ⅱ a. Its bonding to plasma protein and blood vessel endothelium are small , so low-molecular-weight heparin have highly bioavailability and long plasma half-life .