Effect of polymer,plasticizer and filler on orally disintegrating film

Context: Difficulty in swallowing tablets or capsules has been identified as one of the contributing factors to non-compliance of geriatric patients. Although orally disintegrating tablet was designed for fast disintegration in mouth, the fear of taking solid tablets and the risk of choking for certain patient populations still exist.

Objective: The objective of this study was to develop and characterize orally disintegrating film (ODF), which was prepared using different combinations of polymers, plasticizers and fillers.

Materials and methods: Effects of hydroxypropyl methylcellulose (HPMC), polyethylene glycol 400 (PEG 400), glycerin, polyvinyl pyrrolidone (PVP), mannitol and microcrystalline cellulose (MCC) on physical property of ODF formed were studied. The ODF was prepared using the solvent casting method.

Results: Increase in HPMC concentration formed ODF with greater tensile strength. Incorporation of plasticizer (PEG 400 and glycerin) reduced tensile strength but increased elasticity of the ODF formed. PVP increased both tensile strength and elasticity of the ODF. Increase in MCC:mannitol ratio reduced the tensile strength and elasticity of the ODF. Disintegration time of film decreased corresponding to decrease in tensile strength of the film. Formulation R with the optimum tensile strength (13.10?N/mm²), bending flexibility (40 times) and disintegration time (41.50?s) was chosen as final formulation. A total of 80% of the drug was released within five minutes and the ODF was stable at least for one year actual condition.

Conclusion: An ODF containing donepezil HCl was developed and characterized. The donepezil HCl ODF has the potential to improve the compliance of Alzheimer disease patients.     

纤维对混凝土裂缝宽度、曲折度及渗透性的影响

为研究不同纤维（钢纤维（SF）、聚丙烯长纤维（Macro-PP）、聚丙烯短纤维（Micro-PP））对荷载作用下带裂缝混凝土渗透性能的影响,通过劈裂试验引入不同宽度的结构裂缝（50~200 μm）,比较不同纤维对卸载后混凝土裂缝宽度及曲折度的影响。利用自主研发的渗透装置,分析了不同纤维类型、掺量及混杂方式对荷载作用下不同裂缝宽度混凝土渗透性的影响。研究发现:单掺55 kg/m3 SF比25 kg/m3渗透系数降低95.7%。与单掺SF相比,SF和Macro-PP的掺入具有正混杂效应;Micro-PP与SF混杂体系中渗透系数基本无变化,研究表明Micro-PP对结构裂缝间桥接作用甚微,对渗透性的作用不明显。SF和Macro-PP可有效限制裂缝的扩展,增大表面曲折度,降低开裂后混凝土的渗透性。      

复合材料带筋壁板预成型体压缩性与渗透性对树脂流动的影响

以航空碳纤维增强树脂基复合材料典型结构件带筋壁板为研究对象,通过对U3160单向织物的组织结构进行分析,根据纤维束的受压变形状态对其压缩响应进行理论建模,然后以纤维束压缩模型为基础,预测了U3160单向织物按0°/45°/90°/-45°铺层时预成型体在压缩应力作用下厚度变化的响应行为。建立了压缩应力作用下纤维预成型体的渗透率解析模型:在织物压缩模型的基础上,建立了纤维束等效渗透率模型;根据张量理论,分别建立了0°、±45°和90°铺层织物等效渗透率模型;运用渗透介质串并联关系,建立了带筋壁板各特征区域渗透率综合表征模型。基于PAM-RTM流动模拟软件,进行分区渗透率定义,在充模过程中对树脂在带筋壁板预成型体中的流动行为进行模拟,优化工艺参数,确定出最终充模方案,并制作带筋壁板实验缩比件进行成型实验,验证了充模方案的合理性。研究结果为制件的成功制作提供理论依据,从而指导生产实践。