Calvo P, Vila-Jato J L, Alonso M J
Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, University of Santiago de Compostela, Spain.
J Pharm Sci. 1996 May;85(5):530-6. doi: 10.1021/js950474+.
Three different colloidal carriers, namely, nanoparticles and nanocapsules made of poly-epsilon-caprolactone and submicron emulsions, were designed, and their capacity for increasing the comeal penetration of drugs was investigated. The three systems differed in their inner structure and composition, but they had a similar size (200-250 nm) and a negative superficial charge (-16 to -42 mV). Indomethacin, which was used as a model drug, was dispersed at a molecular level within the colloidal systems, no chemical interaction between the polymer and the drug being detected. Release of the encapsulated indomethacin occurred very rapidly upon high dilution in a buffered medium and was independent of the composition of the system. The in vitro comeal penetration of the encapsulated indomethacin was more than 3-fold that of the commercial eye drops. This increased penetration was similar for the three formulations investigated, which therefore excludes the influence of the inner structure or chemical composition of the colloidal systems on the comeal penetration of indomethacin. Thus, it could be stated that the main factor responsible for the favorable comeal transport of indomethacin is the colloidal nature of these carriers rather than their inner structure or composition.
设计了三种不同的胶体载体，即由聚ε-己内酯制成的纳米颗粒和纳米胶囊以及亚微米乳液，并研究了它们增加药物角膜渗透性的能力。这三种体系的内部结构和组成不同，但它们具有相似的尺寸（200 - 250 nm）和负表面电荷（-16至-42 mV）。作为模型药物的吲哚美辛在分子水平上分散于胶体体系中，未检测到聚合物与药物之间的化学相互作用。在缓冲介质中高度稀释时，包封的吲哚美辛释放非常迅速，且与体系组成无关。包封的吲哚美辛的体外角膜渗透性是市售眼药水的3倍多。对于所研究的三种制剂，这种增加的渗透性是相似的，因此排除了胶体体系的内部结构或化学成分对吲哚美辛角膜渗透性的影响。因此，可以说，吲哚美辛角膜转运良好的主要因素是这些载体的胶体性质，而非其内部结构或组成。
