The Pharmacokinetics and Pharmacodynamics of A Novel Recombinant Activated Human Factor VII, GEN-0828, in Hemophilia B Mice.

GEN-0828, a proposed clinical candidate for hemophilia and trauma hemorrhage treatment, is a novel recombinant activated human factor VII (rFVIIa). The purpose of this paper is to compare the pharmacokinetics and pharmacodynamics of GEN-0828 in hemophilia B mice with those of NovoSeven®, the only marketed rFVIIa product worldwide., GEN-0828 and NovoSeven® showed similar affinity bioactivity to recombinant tissue factor (rTF) in vitro. Pharmacodynamics data indicated a generally similar hemostatic efficacy (ED50) of GEN-0828 (10.91 KIU·kg-1) and NovoSeven® (18.91 KIU·kg-1) at the doses studied in hemophilia B mice, while GEN-0828 represented a lower initial effective dosage compared with that of NovoSeven® in terms of both blood loss and APTT. GEN-0828 exhibited linear pharmacokinetic profiles in hemophilia B mice at the 30-338 KIU·kg-1 dose range, the comparative pharmacokinetic study with NovoSeven® indicated better characteristics than NovoSeven® in terms of the appropriate higher maximal concentration (Cmax) and area under the plasma concentration-time curve (AUClast) and longer mean residence time (MRT). In conclusion, GEN-0828 was a promising new type of rFVIIa compound with favourable pharmacokinetic and pharmacodynamic profiles.

Pharmacokinetics and pharmacodynamics of SCT800, a new recombinant FVIII, in hemophilia A mice.

AIM: SCT800 is a new third-generation recombinant FVIII agent that is undergoing promising preclinical study. This study aimed to investigate the pharmacokinetic and pharmacodynamic profiles of SCT800 in hemophilia A mice. METHODS: After hemophilia A mice were intravenously injected with single dose of SCT800 (80, 180, and 280 IU/kg) or the commercially available product Xyntha (280 IU/kg), pharmacokinetics profiles were evaluated based on measuring plasma FVIII: C. For pharmacodynamics study, dose-response curves of SCT800 and Xyntha (1-200 IU/kg) were constructed using a tail bleeding model monitoring both bleeding time and blood loss. RESULTS: Pharmacokinetics profile analysis showed a dose independency of SCT800 ranging from 80 to 280 IU/kg and comparable pharmacokinetic profiles between SCT800 and Xyntha at the doses tested. Pharmacodynamics study revealed comparable ED50 values of SCT800 and Xyntha in the tail bleeding model: 14.78 and 15.81 IU/kg for bleeding time, respectively; 13.50 and 13.58 IU/kg for blood loss, respectively. Moreover, at the doses tested, the accompanying dose-related safety evaluation in the tail bleeding model showed lower hypercoagulable tendency and wider dosage range potential for SCT800 than Xyntha. CONCLUSION: In hemophilia A mice, SCT800 shows comparable pharmacokinetics and pharmacodynamics to Xyntha at the doses tested, and possibly with better safety properties.

[Application of Self-assembling Peptides to Hemostasis].

As a widespread phenomenon in living system, molecular self-assembly has become the meeting point of multidisciplinary research including chemistry, biology, materials science and medicine. In recent years, the rapid development in molecular self-assembly of peptide technology is showing a great potential in the application of tissue engineering, drug delivery, bionic medicine, cosmetology field, optical and electronic product development, etc. Especially, the remarkable hemostatic effect of self-assembling peptides (SAP) on organs, nerves and brain wounds successfully promoted its application to the material science and clinical medicine. This review focuses on the hemostatic effects and characteristics of SAP on different bleeding wound models, action mechanism, its benefits and limitations as well as its adrancing trends.

[Pharmacodynamics and pharmacokinetics of batroxobin in Beagle dog].

Healthy Beagle dogs were administrated with batroxobin by intravenous infusion at high, medium and low doses. The study of pharmacodynamics and pharmacokinetics was intended to clarify the relevance of them and provided strong evidence for clinical use of batroxobin. The blood samples were collected after injection based on the time schedule and samples were tested by ELISA method to get the concentration of batroxobin. At the same time, changes of prothrombin time (PT), thrombin time (TT), activated partial thromboplastin time (APTT), fibrinogen (Fib) and D-dimmer were tested. The results showed that the concentration of D-D increased significantly after administration compared with that of before administration. The main pharmacokinetic parameters were as follows: t1/2 were (2.27 +/- 0.42) h, (10.65 +/- 2.19) h and (11.01 +/- 3.51) h; C(max) were (11.9 +/- 1.72) ng x mL(-1), (154.53 +/- 12.38) ng x mL(-1) and (172.14 +/- 47.33) ng x mL(-1); AUC(last) were (29.38 +/- 3.69) ng xh x mL(-1), (148.43 +/- 72.85) ng x h x mL(-1) and (599.22 +/- 359.61) ng x h x mL(-1). The elimination of batroxobin was found to be in accord with linear kinetics characteristics. The results of pharmacodynamics showed that D-dimmer level increased significantly after the administration of batroxobin, which was similar with the changes of batroxobin plasma concentration. Simultaneously, Fib concentrations in Beagle dog blood decreased significantly after the iv administration of batroxobin, while recovered to base level after 48 hours. PT, TT and APTT significantly became longer after administration, which returned to normal level after 48 hours. Especially, the D-dimmer levels and the batroxobin concentration in plasma after intravenous infusion of the drug were synchronized in Beagle dogs. Changes between PD/PK results had obvious correlation, and the D-dimmer levels in plasma can be one of the important monitoring indicators of batroxobin in thrombolytic medication.

Enhanced oral bioavailability and anti-tumour effect of paclitaxel by 20(s)-ginsenoside Rg3 in vivo.

The purpose of this study was to investigate the effect of paclitaxel in combination with 20(s)-ginsenoside Rg3 on its anti-tumour effect in nude mice. In the Caco-2 transport assay, the apparent permeability from the apical side to the basal side (P(app)) (A-B) and P(app) (B-A) of paclitaxel were measured when co-incubated with different concentrations of 20(s)-ginsenoside Rg3. The results indicated that the penetration of paclitaxel through the Caco-2 monolayer from the apical side to the basal side was facilitated by 20(s)-ginsenoside Rg3 in a concentration-dependent manner. Meanwhile, 20(s)-ginsenoside Rg3 inhibited P-glycoprotein (P-gp), and the maximum inhibition was achieved at 80 µM (p < 0.05). The pharmacokinetic parameters of paclitaxel after oral co-administration of paclitaxel (40 mg/kg) with various doses of 20(s)-ginsenoside Rg3 in rats were investigated by an in vivo pharmacokinetic experiment. The results showed that the AUC of paclitaxel co-administered with 20(s)-ginsenoside Rg3 was significantly higher (p < 0.001 at 10 mg/kg) compared with the control. The relative bioavailability (RB) % of paclitaxel with 20(s)-ginsenoside Rg3 was 3.4-fold (10 mg/kg) higher than that of the control. The effect of paclitaxel orally co-administered with 20(s)-ginsenoside Rg3 against human tumour MCF-7 xenografts in nude mice was also evaluated. Paclitaxel (20 mg/kg) co-administered with 20(s)-ginsenoside Rg3 (10 mg/kg) exhibited an effective anti-tumour activity with the relative tumor growth rate (T/C) values of 39.36% (p <0.05). The results showed that 20(s)-ginsenoside Rg3 enhanced the oral bioavailability of paclitaxel in rats and improved the anti-tumour activity in nude mice, indicating that oral co-administration of paclitaxel with 20(s)-ginsenoside Rg3 could provide an effective strategy in addition to the established i.v. route.

Quantitative determination of acetylshikonin in macaque monkey blood by LC-ESI-MS/MS after precolumn derivatization with 2-mercaptoethanol and its application in pharmacokinetic study.

AIM: To develop and validate a novel precolumn derivatization method for the quantitative determination and pharmacokinetic application of acetylshikonin in macaque monkeys by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). METHODS: 2-Mercaptoethanol was added to the blood sample as the derivatization reagent. The derivatization reaction formed 1 major derivation product, which was well correlated with acetylshikonin. The acetylshikonin concentrations in the biological samples were calculated by quantitative determination of the major derivation product using LC-ESI- MS/MS. Separation was achieved using a C18 column (2 mm x 50 mm, 5 microm) at room temperature and a linear gradient elution with a mobile phase containing methanol (1.96% acetic acid) and 10% methanol in water (1.96% acetic acid and 10 mmol/L ammonium acetate) at a flow rate of 0.2 mL/min. In addition, the major derivative, named derivative III, was identified by UV spectra, MS, and the (1)H-NMR and (13)C-NMR spectra. RESULTS: Good linearity was obtained within the range of 5 and 2000 ng/mL (r>0.99 using a linear regression model with 1/x2 weighting) for acetylshikonin. The interday and intraday precisions were found to be less than 12.3%, with the exception of the lowest concentration, which was less than 17.2%. The interday and intraday accuracies, which were between -3% and 0.6%, were also observed. After the administration of acetylshikonin (80 mg/kg, po) in macaque monkeys, the pharmacokinetic parameters were obtained through the non-compartmental analysis, where the area under the concentration-time curve to the last measurable concentration, the terminal elimination halflife, and the mean residual time were 615.4+/-206.5 ng x dh/mL,12.3+/-1.6 h, and 10.2+/-0.7 h, respectively. CONCLUSION: The method was validated and applied to the quantitative determination and pharmacokinetic study of acetylshikonin in the blood samples of macaque monkeys.