Study On Intravital Magnetic Targeted Specificity And Sustained Release Effect Of Dextran-magnetic LDH-Fluorouracil Transshipment Model In Rats

1 Study on targeted-specificity of Dextran-Magnetic LDH-Fluorouracil model in vivoWith a supermolecule model of dextran-magnetic LDH-fluorouracil as magnetic targeted drug delivery system, the magnetic targeting drug bio-distribution of this transfering model in rats was studied. A HPLC internal labeling method had been established to determine the concentration of 5-Fu in tissues. Ultraviolet spectro-photometry, flame atomic absorption spectrometer and the inductively coupled plasma were used to detect the iron concentration in tissues, and Prussian blue iron staining was employed for observing the difference of iron bio-distribution in tissues. The results shown that the established HPLC internal standard method had good recovery rate and precision, after administration via peritoneal injection, the drug concentration were significant higher in both right back and head where the magnetic field had been set up, than in other parts which were far away from the magnetic field. Drug concentration distribution shown statistical significance, and proved that the ternary composite model had an ideal magnetic targeted transfering effect. The data reported here suggest that under the influence of an external magnetic field, the Dextran-Magnetic LDH-Fluorouracil can be significantly enriched in the target area, and show good magnetic targeted-specificity.2 Study on intravital sustained-release effect of Dextran-Magnetic LDH- Fluorouracil modelWith an objective to study the sustained-release function of the transfer model of Dextran-Magnetic LDH-Fluorouracil in rats, the HPLC internal standard method had been established to test the plasma concentrations of 5-Fu in rats after administration, and the pharmacokinetic experimental data were analysed with the software of DAS 2.0. The results demonstrated that the concentration-time curve of fluorouracil group shown single peak with a two-compartment model, but that of the LDH group shown multi-peak with a multi-compartment model, in which the 1st peak shown two-compartment model, while others shown single compartment model. The fluorouracil group presented drug peak at 10 minutes, but LDH group presented the 1st drug peak at 6h which was 36 times of that of fluorouracil group; the half time of fluorouracil group was 1.16h, but that of LDH group was 3.53h which was 3.06 times of that of fluorouracil group. The data reported here suggest that Dextran-Magnetic LDH-Fluorouracil transfer model can change pharmacokinetic action of 5-Fu after injection into animals, and will show good intravital sustained-release effect in vivo.