机械活化改性果胶骨架片的制备及释放特性研究

Study on Preparation and Release Characteristics of Pectin Matrix Tablets Modified by Mechanical Activation

以果胶为原料,采用机械活化法改性,研究了机械活化时间对果胶水溶性和溶胀性的影响,制备了骨架片,探讨了粘合剂、钙盐种类、机械活化时间、载药量和压片压力对骨架片制备的影响,通过BSA含量的测定,研究了机械活化骨架片的释放特性。机械活化改性,降低了果胶的水溶性和溶胀度;骨架片的最佳工艺,0.025g MA 8h,0.008g BSA,0.025g甲基纤维素,0.008g CaSO4与0.001g硬脂酸镁,压片压力8kg·mm-2。机械活化改性果胶骨架片具有更高的化学活性,能使骨架片外表层迅速形成致密凝胶层,与水溶性小的CaSO4形成果胶钙沉淀,有效地减缓水分在骨架片中的扩散。药物在凝胶层膜内溶解并饱和,通过自由扩散作用向膜外扩散。而薄的凝胶层中浓度梯度大,药物快速释放到介质中,表现为药物的初始释放度大。机械活化改性果胶致密而薄的凝胶层和果胶钙沉淀的egg-box空间网状结构大大降低了溶剂的扩散作用,药物释放速度减慢并最终趋于稳态,表现为骨架片释药速度的恒定。

In this paper,using pectin as raw material,modificating pectin with the mechanical activation method,the influences of mechanical activation time on the solubility and swelling property of pectin were studied.Matrix tablets were preparated and the influences of adhesive,calcium salt,mechanical activation time,load and pressure on the preparation of matrix tablets were studied.After mechanical activated,the water solubility and swelling property of pectin was decreased;the optimal process of matrix tablets was 0.025 g MA 8h,0.008 g BSA,0.025 g methyl cellulose,0.008 g CaSO4,0.001 g magnesium stearate,tabletting pressure 8kg·mm-2.The mechanical activation modified pectin matrix tablets had a higher chemical activity,which can make the surface layer of the framework rapidly form a dense gel layer,which form the pectin calcium precipitation with CaSO4 to slow down the diffusion of water in the matrix effectively.The drug is dissolved and saturated in the gel layer,and the drug diffusion through the free diffusion.However,the concentration gradient is large in the thin gel layer and the drug is released into the medium quickly,which was the performance of large initial release of the drug.The thin gel layer and egg-box space network structure of pectin calcium precipitation greatly reduces the diffusion of solvent,and drug release rate slowing down and tending to steady state eventually,which performance as a constant speed of matrix release.