Study On The Release In Vitro And In Vivo Of Super Streptomycin Suifate PELA Microspheres

Streptomycin sulfate as an amino glycoside antibiotic has strong antibacterial effect on mycobacterium tuberculosis; however, its main side effect is caused function damage on vestibular nerve, acoustic nerve and kidney. For these reasons, the clinical application of streptomycin sulfate is be limited, especially in the treatment of children's pulmonary tuberculosis. With the rapid development of release technology, the drugs can be released slowly. Compared with the corresponding normal preparations, the dosing frequencies will reduce or reduce at least half, at the same time; it also can significantly increase patient compliance or efficacy,moreover, magnetic drug targeting shows great prospects in improving the targeting of drugs on the lesion and reduce the toxic side effects of drug.A superparamagnetic magnetic microsphere which has good compliance can be guided by external magnetic field; moreover, it can be well dispersed when external magnetic field does not exist. PELA is a Poly (ethyleneglycol)-co-poly (d, l-lactide) which has good biodegradability and biocompatibility. In this experiment, streptomycin sulfate will serve as a model drug, using PELA as microspheres material which parcel with streptomycin sulfate and superparamagnetic Fe3O4 nanoparticles, and then superparamagnetic PELA microspheres of streptomycin sulfate will be created. This experiment will research on its vitro and vivo emancipation.PartⅠThe Preparation of Superparamagnetic PELA microspheres of streptomycin sulfate.In this section, the superparamagnetic PELA microspheres of streptomycin sulfate will be created by double emulsion solvent evaporation method. At the same time, the content of Streptomycin sulfate which will be test by UV spectrophotometry, the encapsulation efficiency and drug loading of superparamagnetic PELA microspheres of streptomycin sulfate will be calculated and established. The optimum preparation will be selected. The average encapsulation efficiency was 52.51%, the average drug loading was 10.47%, the average intensity of the magnetic response of 2.17 emu / g, and average particle size is 1.691μm.PartⅡThe research on superparamagnetic PELA microspheres of streptomycin sulfate's vitro emancipation.The small cup method from"Chinese Pharmacopoeia"will be used to test vitro emancipation. Drug release will divide into three groups: group A is blank PELA microspheres of streptomycin sulfate, as a blank comparing object; group B and C are superparamagnetic PELA microspheres of streptomycin sulfate. Oscillating magnetic field generator will be added in group C to interfere 15 minutes before sampling. The result shows that through the interference oscillating magnetic field generator, the drug emancipation of group C which has superparamagnetism was significantly higher than the group A and B.PartⅢThe research on superparamagnetic PELA microspheres of streptomycin sulfate's vivo emancipation.This section investigates the vivo emancipation in each microspheres through the microsphere intramuscular injection experiment in rabbits (equivalent to the microspheres containing streptomycin sulfate / test rabbit body weight = 16mg/kg), and pulse oscillating magnetic field generator. The Superparamagnetic streptomycin PELA microspheres will be injected in group A and B, and streptomycin sulfate will be injected in group C. suppose that each group taking whole blood 0.1ml from each sampling point in 48 sampling time which from 5 minutes to 12 hours. On the eighth and tenth sampling point, the oscillating magnetic filed will be added in group A for 15 minutes. The result shows that the drug emancipation in superparamagnetic PELA microspheres of streptomycin sulfate can increase through the interference of oscillating magnetic field generator.