Figure 2: Alginate and Si-HPMC particle diffusion properties. Alginate and Si-HPMC particles were incubated in fluorescently labeled FITC-dextran (Mw 20, 250, and 2000 kDa) solutions for 2 h and 30 min. Fluorescence intensities of particles (inside) and FITC-dextran solutions (outside) were assessed by confocal microscopy. A ratio of internal to external fluorescence was then calculated, and a ratio of 1 indicating that fluorescence intensity was identical in a particle and the surrounding solution. Alginate and Si-HPMC particles of 1 mm diameter were selected for this study. Each test was performed for one particle at a time and repeated at least 3 times.