含布洛芬的碳酸钙@磷酸八钙颗粒的制备及药物释放行为

Synthesis of calcium carbonate@octacalcium phosphate powders with encapsulation of ibuprofen and its release behavior

采用气相扩散法制备得到含布洛芬的碳酸钙（CaCO3-IBU）微球，并通过 Pechini 工艺沉积磷酸八钙（OCP）壳层后制备得到含 IBU 的碳酸钙/磷酸八钙（CaCO3-IBU＠OCP）.IBU 的添加量对 CaCO3-IBU 的物相和形貌有显著影响，这因为 IBU 的电离消耗 OH－离子，从而对 CO2气体的溶解、CO2－3离子的产生和 CaCO3-IBU的结晶行为都产生影响.在磷缓冲液（pH 值＝7．2～7．4）和 lysosome-like 缓冲液（pH 值＝4．7）中 IBU 自CaCO3-IBU＠OCP颗粒内释放的行为对溶液pH 值和OCP壳层结构（受柠檬酸、聚乙二醇及其分子量因素影响）敏感，这与IBU分子与CaCO3的作用机制及壳层内键合分子的位阻作用对IBU的扩散产生阻碍有关.

Calcium carbonate with encapsulation of ibuprofen （CaCO3-IBU）was firstly prepared by a facile va-por diffusion method,and was then coated with a shell of octacalcium phosphate （OCP）through a modified Pechini process.The phase and morphology of CaCO3-IBU were significantly varied with the amount of IBU ad-dition because the solubility of IBU after consumption of OH- ions influenced the solubility of CO2 gas,the generation of CO2-3 ions and crystallization of CaCO3-IBU.In phosphate buffered saline （pH=7.2-7.4）and lyso-some-like buffers （pH=4.7）,the release behavior of IBU from CaCO3-IBU@OCP was sensitivity with the pH value of culture solution and the structure of OCP shell,which was varied with molecular weight of PEG, amount of citric acid and polyethylene glycol addition.The mechanism for the improved sustained-release profile was caused by the interaction between ibuprofen and CaCO3 ,as well as the steric hindrance of core-shell struc-tured drug delivery on the outward diffusion of IBU molecules.