Study On Sustained Release PLGA Microsphere With Biodegradation Of Gatifloxacin

Objective: Choosing fourth-generation fluoroquinolone gatifloxacin drug (gatifloxacin, AM-1155) as model drug to study PLGA as carrier Gatifloxacin biodegradable sustained-release formulations. And then to Determinate the content of microspheres, preparation and prescription of optimization, in vitro release, stability, and so on. In order to extend gatifloxacin partial duration antimicrobial activity through the preparation of gatifloxacin microsphere formulations.Methods: The HPLC method was used to establish gatifloxacin and its preparation for the determination and the establishment of relevant quality standards. Before the prescription, physical and chemical properties and stability of gatifloxacin was studied. In this paper, PLGA was used as carrier material, the emulsion-solvent evaporation method was used to prepare of gatifloxacin microspheres. The index for quality assessment, such as entrapment efficiency, drug loading, the yield, particle size and its distribution was used to study gatifloxacin prescription microspheres factors and processes single-factor study, on the basis of the design selected by orthogonal optimal prescription. The morphology, entrapment efficiency, drug loading, the yield, particle size and stability of gatifloxacin microsphere evaluated and studied for the optimization of prescription.Preparation of the optimal prescription of gatifloxacin PLGA microspheres in vitro release studies, release of different media were studied, under different conditions of release in vitro release, the evaluation of microspheres prepared from the in vitro release effect.Results: The HPLC was established for gatifloxacin drug-related properties, stability of microsphere, determination of drug loading and entrapment efficiency. The results of prescription before the study showed that at 25℃gatifloxacin solubility in water for the balance of 10mg/mL. In the solid state under high temperature, humidity and light instability, Gatifloxacin occurred to degradate, reduce the content. Gatifloxacin in acetone-water (1:9) solution was stable for 7 days.Through single-factor test and orthogonal experimental study of gatifloxacin PLGA microspheres and optimized prescription process, under the optimal conditions, six groups of gatifloxacin PLGA microspheres samples was obtained for drug loading 2.00±0.10 %, entrapment efficiency 98.98±2.75%. The results of microscope observation was the size of uniform microspheres, particle roundness, surface smooth. Determination of the preliminary showed that the stability of drug-containing microspheres in light, temperature 40℃, humidity 95% was more stable .The HPLC method was established for in vitro release of microsphere determination; In vitro release of microsphere method was establish, a pH7.4 phosphate buffer solution medium for the release of the dialysis method of in vitro release preparations was determined. The results showed that in vitro release of microspheres under the conditions had no burst effect, with significant sustained-release effect , and can be sustained in vitro release time to reach 15 days.Conclusion: In this paper, the HPLC method was was convenient, sensitive and accurate. It answer for requirements of sample analysis and provides a reliable analysis to prescription drug design, evaluation agent. Through the prescription of pre-mastered physical and chemical properties of gatifloxacin , the preparation of microspheres had been supported. With a certain degree of drug loading, high encapsulation efficiency and significant effect of in vitro release by the optimization of prescription gatifloxacin PLGA microspheres, the subject has reached a expectant target.