Preparation And Optimization Of Poorly Soluble Drug Loaded Using Mesoporous Silica Nanoparticles As Carriers System

Drugs can be absorbed by intestines and stomach only when they are dissolved.Many drugs have low oral bioavailability because of their poor solubility whichresults in their limited application. Several well-established methods have been used,e.g. inclusion complex, solid dispersion, nanoparticle dispersion, co-grind.Nevertheless, they always have poor drug loading and stability. Entrapping drugs intothe highly ordered mesoporous silica nanoparticles is perhaps a method to increasetheir water-solubility and stability. Mesoporous silica nanoparticles which have highsurface areas, tunable pore sizes with narrow distributions, well-defined surfaceproperties, low toxicity and very good biocompatibility, are suitable to work as anattractive reservoir for lipid soluble molecules. Two kinds of insoluble drugs(Ibuprofen and β-carotene) have been studied to select suitable carriers.A series of mesoporous silica nanoparticles with different proe sizes have beensynthesized, and the mesoporous surface was modified with silane coupling agent3-aminopropyltriethoxysilane. All the mesoporous materials were characterized bymeans of fourier transform-infrared spectroscopy, scanning electron microscopy,elemental analysis and nitrogen adsorption-desorption technique. The results showedthat mesoporous silica nanoparticles exhibited the silimilar spherical particles andtunable pore sizes with narrow distributions, which is suitable to be used for drugcarriers system. We also investigated the influence of ultrasonic time on removing thetemplet, then obtained the optimum conditions.Then mesoporous silica nanoparticles were used as carriers of ibuprofen to studythe influence of mesoporous structure and superficial properties on loadingmechanism. Mesoporous materials before and after drug loading were characterizedby means of elemental analysis and fourier transform-infrared spectroscopy. The drugloading and release have been measured. The drug loading in nanoparticles withlarger mesoporous channels was more than those with small channels. In addition,when mesoporous surface was grafted with polar groups, the drug loading increasedobviously. Drug release exhibited obviously increase when ibuprofen was loaded intothe mesoporous silica nanoparticles.When mesoporous silica nanoparticles were used as the carriers of β-carotene,the drug loading in nanoparticles with larger mesoporous channels was higher, whichmeans the pore size of mesoporous materials is also an important factor to obtain large drug loading. Kinds of parameters that affacted the drug loading had beeninvestigated. Besides, the physicochemical stability of β-carotene powders had beenimproved by the adsorption of chitosan. The results implied that chitosanconcentration had a significant impact on the stability of β-carotene. In addition, therelease amount of β-carotene had also been improved by the adding of chitosan.