Islam Nazrul, Stewart Peter, Larson Ian, Hartley Patrick
Department of Pharmaceutics, Victorian College of Pharmacy, Monash University, Parkville, Victoria 3052, Australia.
J Pharm Sci. 2005 Jul;94(7):1500-11. doi: 10.1002/jps.20381.
Adhesion force distributions of silica spheres (5 and 20 microm) and salmeterol xinafoate (4 microm) particles with inhalation grade lactose surfaces and spin coated lactose films were determined by atomic force microscopy (AFM) to investigate the influence of surface roughness on the force distributions. The roughness of lactose particles and films was determined by both AFM and confocal microscopy (CM); the lactose particles showed RMS R(q) values between 0.93 and 2.2 microm. The adhesion force distributions for silica and SX probes were significantly different for the different lactose carriers and broad, e.g., the adhesion force distribution between a 5 microm silica sphere and lactose particles ranged from 5 to 105 nN. This contrasted with distributions on smooth spin coated lactose films (RMS R(q) of 0.28 nm) which were not significantly different and were narrow, e.g., the adhesion force distribution between a 5 microm silica sphere and spin coated lactose films was between 42 and 68 nN. In addition, no significant difference in adhesion force distribution occurred with silica probe size on the lactose carrier surface. The use of X-ray photoelectron spectroscopic analysis confirmed that the lactose surfaces were free of impurities that might contribute to variation in adhesion. Although the almost atomically flat films showed some adhesion variability, the surface roughness of the lactose particles was a major contributing factor to the broad distributions seen in this study.
通过原子力显微镜（AFM）测定了二氧化硅球体（5微米和20微米）以及昔萘酸沙美特罗（4微米）颗粒与吸入级乳糖表面和旋涂乳糖膜之间的粘附力分布，以研究表面粗糙度对力分布的影响。乳糖颗粒和膜的粗糙度通过AFM和共聚焦显微镜（CM）测定；乳糖颗粒的均方根粗糙度R(q)值在0.93至2.2微米之间。对于不同的乳糖载体，二氧化硅和昔萘酸沙美特罗（SX）探针的粘附力分布存在显著差异且范围较宽，例如，5微米二氧化硅球体与乳糖颗粒之间的粘附力分布范围为5至105纳牛。这与光滑旋涂乳糖膜（均方根粗糙度R(q)为0.28纳米）上的分布形成对比，后者差异不显著且范围较窄，例如，5微米二氧化硅球体与旋涂乳糖膜之间的粘附力分布在42至68纳牛之间。此外，在乳糖载体表面，二氧化硅探针尺寸对粘附力分布没有显著影响。X射线光电子能谱分析的结果证实，乳糖表面不存在可能导致粘附力变化的杂质。尽管几乎原子级平整的膜表现出一定的粘附力变异性，但乳糖颗粒的表面粗糙度是本研究中观察到的宽分布的主要促成因素。
