蒙脱石对胰岛素的吸附及其缓释性能研究

以提纯后的钠基蒙脱石为研究对象,在一定条件下制备出胰岛素/蒙脱石复合物(insulin/montmorillonite,INS/MMT),研究钠基蒙脱石对胰岛素的吸附能力,考察pH值和释放时间等因素对载药复合物体外释放胰岛素的影响规律.通过3种体外释放模型对其释药数据进行拟合,探讨了复合物中胰岛素的释放机理,说明了蒙脱石作为胰岛素缓释载体的可行性.实验结果表明:蒙脱石对胰岛素有较好的吸附能力,复合物对INS的体外释放能力主要受释放介质pH值的影响,当pH 7.4时,胰岛素的释放浓度和累积释放量最大,分别为181.713mg/L和14.54%,在pH 5.0时的结果最小;一级动力学模型能比Korsmeyer-Peppas模型和Higuchi模型更好地拟合胰岛素在不同pH下的体外释放情况;拟合结果表明:胰岛素从复合物中释放出来的行为主要由扩散作用决定.

Study on the Adsorption and Sustained-Release Performance of Na-Montmorillonite for Insulin

Insulin/montmorillonite(INS/MMT)complexes were prepared by purified Na-montmorillonite and insulin under a certain condition.The absorption ability of Na-montmorillonite was analysed,and the effects of pH and time on INS release from the complexes were explored.Three models of in vitro drug release were used to simulate the release performance of INS-loaded complexes.The release mechanism of INS from the complexes and the feasibility of MMT as the sustained-release drug carrier were discussed.The results showed that MMT had a high absorbability.In vitro release ability of INS from the complexes was affected by pH value of the release solution.The maximum concentration and the in vitro cumulative amount of INS released from the complexes at pH 7.4reached 181.713mg/L and 14.54%,and the lowest is at a pH value of 5.0.The first order kinetics model was better used to describe the variation of in vitro release rate of INS with time at different pH values,compared to the Korsmeyer-Peppas and Higuchi models.It is suggested that the release process of INS from the complexes in various solutions mainly depends on the physical diffusion.