Résumé
Monoclonal antibody ( mAb ) represents a class of therapeutics experienced dramatic development over the past 30 years. Because of the tremendous differences in physicochemical and biological properties between mAbs and small molecules, the mAb therapeutics significantly differ from the chemical drugs in pharmacokinetic characteristics and underlying mechanisms. Full understanding of those characteristics and mechanisms may efficiently guide the screening and development of mAb medi-cines, and would well support their safety evaluation and clinical dosage regimen designing. This review is to summarize pharma-cokinetics and underlying mechanisms of mAbs from the aspects of absorption, distribution and elimination, as well as the ap-proaches for prediction of mAb pharmacokinetics in humans.
Résumé
Aim To establish a combined method ofβ-glucuronidase hydrolysis and LC-MS-MS analysis for the determination of scutellarein in human plasma, and investigate the pharmacokinetics of scutellarin prepara-tion in healthy male volunteers. Methods Plasma samples were prepared by enzymolysis with β-glucu-ronidase and protein precipitation with methanol. The analytes scutellarein and quercetin ( IS ) were separa-ted on an Agilent ZORBAX SB C18 column ( 2. 1 mm × 150 mm, 5 μm) with the mobile phases consisting of acetonitrile, methanol and water. Multiple reaction monitoring ( MRM) on MS was used to monitor precur-sor to produce ion transitions of m/z 285. 0→136. 8 for scutellarein and m/z 301. 1→120. 8 for IS. After method validation, this method was applied to deter-mine the plasma concentration of scutellarein in 12 male volunteers following single oral administration of 120 mg scutellarin preparation. Drug And Statistic soft-ware (1. 0) was used to process data and the pharma-cokinetic parameters were calculated. Results The assay was validated with linear range of 4 . 01-513. 38μg · L-1 for scutellarein. The intra- and inter-batch precisions ( RSD%) were within 7. 22%. The absolute recoveries were more than 84. 23%. The pharmacoki-netic parameters after a single dose were as follows:Cmax (μg · L-1 ): 159. 97 ± 58. 14; AUC(0-19) (μg · L-1·h):1151. 37 ±279. 80; AUC(0-∞)(μg·L-1· h):1194. 13 ± 264. 51; Tmax ( h):6. 33 ± 1. 67; T1/2 (h):2. 83 ± 0. 60. Conclusion The assay method is proved to be sensitive, accurate and convenient. It can be successfully applied to a pharmacokinetic study of scutellarin in healthy male volunteers.
Résumé
Constant infusion, exponentially declining infusion and program infusion of theophlline were administered to rabbits byadopting the rabbit population pharmacokinetic parameters in this laboratory, and the plasma concentrations of the drug was measured by ul- traviolet spectrophotometry. The results showed that the plasma drug concentrations following exponentially declining infusion and program infusion attained the desired steady-state level at only 30 min, though the T1/2?= 6. 08h, The median absolute value of performance error in pro-gram infusion and exponentially declining infusion was 7. 8% and 14% respectively.