| Diclofenac sodium and celecoxib are the two main anti-inflammatory drugs for the treatment of rheumatoid arthritis,and they can be made into sustained-release preparations to solve the problem of continuous administration for many times effectively.The liposomes,micelles,etc.are commonly used sustained-release carriers.However,they have poor stability and low drug loading.Due to the safe features,mesoporous carbon carriers have adjustable pore structures and easily modifiable surface properties,and have been seen as promising carrier for sustained-release preparations.Herein,to improve the loading and sustained release performance of the above two drugs,a sustained release preparation with mesoporous carbon as drug carriers was designed.Moreover,the loading and sustained release performance of drugs was preliminarily studied by adjusting the mesoporous structure and carbon sphere element doping.1)Hollow mesoporous carbon spheres were prepared using a hard template strategy.Using polystyrene spheres as templates and carbon sources,and colloidal silica as silica sources,the assembly of the two was initiated by adjusting the p H of the aqueous solution,and the usage of colloidal silica was changed to synthesize hollow mesoporous carbon spheres of multiple sizes.As drug carriers for diclofenac sodium and celecoxib,the results showed that the polystyrene spheres encapsulated in 0.8 m L colloidal silica had a complete spherical structure,and the drug loading capacities for diclofenac sodium and celecoxib were 110.09±0.89 μg/mg and 104.17±1.64 μg/mg,respectively,and the release rates after12 hours were 95.43%±1.67% and 91.96%±2.24%,respectively.2)A combination of hard templates and elemental doping was used to prepare nitrogen doped hollow mesoporous carbon spheres.During the experimental process,the hollow structure of carbon spheres obtained from polystyrene spheres and the in-situ polymerization of dopamine on the template surface were combined to customize different thicknesses of silica layers,providing limited pyrolysis space for the preparation of nitrogen doped hollow mesoporous carbon spheres.As drug carriers for diclofenac sodium and celecoxib,the results showed that the carbon carrier obtained from the pyrolysis of 0.1 m L of orthosilicate acid tetracthyl ester formed a silicon shell,which contained 4.16% nitrogen content.The drug loading capacities for diclofenac sodium and celecoxib were 125.34±0.88μg/mg and 96.55±1.26 μg/mg,respectively,and the drug release rates after 12 hours were96.42%±1.98% and 90.29%±2.16%,respectively.3)Nitrogen doped porous carbon spheres were synthesized.Dopamine hydrochloride,a nitrogen rich raw material,was designed to be polymerized into spheres in aqueous solution.Mesoporous structure was created by the cooperation of nanoemulsion and orthosilicate acid tetracthyl ester.And nitrogen doped carbon spheres with porous structure were prepared as drug carriers to explore the loading and release performance of model drugs.The results showed that the nitrogen doping amount of the carbon carrier was 6.91%,and the drug loading amounts for diclofenac sodium and celecoxib were 104.36±1.59 μg/mg and 95.63±1.94 μg/mg,respectively,and the drug release rates after 12 hours were94.91%±1.78% and 90.10%±2.04%,respectively.Based on the loading and release results of the three carbon materials mentioned above,from the perspective of material structure,hollow cavities with large specific surface area and nitrogen element doping become the preferred drug carriers for adsorption/release of diclofenac sodium.The hollow structure with large mesoporous channels enhances the ability to load celecoxib.In summary,hollow structures with mesopores and nitrogen doping characteristics are more conducive to improving drug loading capacity and controlling drug release behavior.The inorganic mesoporous carbon nanomaterials prepared in this experiment serve as sustained-release carriers,greatly improving the defect of short half-life of diclofenac sodium and exhibiting good solubilization effect on celecoxib.By designing sustained-release formulations of diclofenac sodium and celecoxib,it has been demonstrated that mesoporous carbon materials are feasible as drug carriers. |
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