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Meloxicam (Meloxicam) is a new type of non-steroidal anti-inflammatory drugs (NSAIDs), is a new and safe anti-inflammatory drugs, meloxicam pharmaceutical dosage forms and more for the immediate-release oral absorption incomplete, limiting its clinical application. In order to extend the time of the release of meloxicam extended dosing interval to maintain effective therapeutic concentrations, through molten prepared carrier material polylactic acid, its preparation meloxicam release microspheres as carrier materials, to achieve long-term sustained release purposes. Polylactic acid melt polymerization preparation of carrier material of catalyst, temperature and reaction time on product, and by the infrared (IR), nuclear magnetic resonance (1H-NMR), gel permeation chromatography (GPC) and other means of synthetic polylactic acid characterize the get best optimization process. Under optimum conditions: the amount of stannous octoate 0.6% (accounting for the quality of the lactic acid), reaction temperature of 170 ° C, polycondensation time of 10 hours. Product as measured by gel permeation chromatography (GPC), the polylactic acid having a number average molecular weight of around 6000, and the mass average molecular weight of about 17,000. Using solvent evaporation prepared microspheres, polylactic acid as a carrier, and dichloromethane as the organic solvent, polyvinyl alcohol as a dispersing agent. Summarizes the influencing factors of the microsphere preparation using dichloromethane: organic solvents, its high volatility; emulsifier selected polyvinyl alcohol (PVA), the surface morphology of the microspheres obtained is better, more uniform particle size distribution; stirred The speed is increased, the average particle size of the microspheres is reduced. By single factor and orthogonal experiment to optimize the process of the preparation of drug-loaded microspheres: PVA concentration of 2% PLA concentration of 0.04 g / mL, MLX: PLA 1:6 (mass ratio), ratio of water and oil 250:1, magnetic stirring, and the stirring speed of 800 rpm, the solvent evaporation time of 3 hours. Microscope, scanning electron microscope, the surface morphology of the microspheres, and the particle size distribution analysis Characterization microspheres monodispersed sphere, the particle diameter of between 100μm ~ 150μm. Drug loading, encapsulation efficiency results showed that the drug loading (11.39 ± 0.83)%, encapsulation efficiency was (71.86 ± 0.1)%. Release medium in a phosphate buffer solution, using UV spectrophotometer to study the in vitro release performance. Vitro release experiments show that the drug-loaded microspheres obtained in the previous four hours has a certain burst release, burst release is about 30%, and then begin a slow release, the first 4 days of the drug-loaded microspheres accumulated release rate of about 68% in 10 days about 85%, indicating that meloxicam / PLA microspheres have a better sustained release. The study found that the release time is increased, with the microsphere diameter increases with increasing pH of the release medium is increased, with the polyvinyl alcohol concentration increases and decreases.
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