In vitro release studies are commonly used to assess the product performance of topical dosage forms. In such studies, the mass transport of drugs through synthetic membranes into a receiving chamber filled with a release medium is measured. The release medium is also passed through filtration membranes prior to chromatographic analysis. There are no official guidelines directing membrane selection for in vitro release studies or for filtration. Considering the diversity in membrane materials and their physical properties, the aim of this study was to investigate membrane-drug binding and the effect of various membranes on the release performance of a model drug dexamethasone (DEX) using USP dissolution apparatus IV. Seven membranes of different pore sizes (0.45 and 1.2 μm) and materials (cellulose acetate, polyethersulfone, and nylon) were assessed. Two different methods, syringe filter and 24-h incubation, were used for the determination of membrane-drug binding effects at low drug concentrations and saturated concentration conditions. Cellulose acetate and nylon membranes showed significant drug binding after 24-h incubations at both drug concentrations. DEX diffusion through membranes was significantly slowed down in all the tested membranes when compared with DEX solution without membranes. The extent of the retardation varied due to the differences in membrane structures. In conclusion, materials and sources of membranes affected drug dissolution profiles and the results showed membrane-drug binding effects. Proper selection of membranes with low drug binding ability and low diffusion resistance is essential to ensure appropriate and reproducible in vitro release assessments and filtration studies.

体外释放研究通常用于评估局部剂型的产品性能。在这样的研​​究中，测量了药物通过合成膜向装有释放介质的接收室的大量传输。在色谱分析之前，释放介质还应通过过滤膜。没有官方指导指导体外膜的选择发布研究或进行过滤。考虑到膜材料的多样性及其物理性质，本研究的目的是研究膜-药物结合以及使用USP溶出度仪IV研究各种膜对模型药物地塞米松（DEX）释放性能的影响。评估了七个具有不同孔径（0.45和1.2μm）和材料（醋酸纤维素，聚醚砜和尼龙）的膜。在低药物浓度和饱和浓度条件下，使用两种不同的方法，即注射器过滤器和24小时孵育来确定膜-药物结合作用。在两种药物浓度下孵育24小时后，醋酸纤维素膜和尼龙膜均显示出显着的药物结合力。与没有膜的DEX溶液相比，在所有测试的膜中，通过膜的DEX扩散明显减慢。延迟的程度由于膜结构的差异而变化。总之，膜的材料和来源影响药物的溶出度，结果表明膜-药物结合作用。正确选择具有低药物结合能力和低扩散阻力的膜对于确保适当和可重复的生产至关重要体外释放评估和过滤研究。