Controlled Drug Release from Polyether Poly (urethane urea)

The drug release profiles from PEUUs were examined in terms of the interaction between device and drug in the release system. Crystal violet (CV) was used as a model drug, and polyether poly (urethane urea) (PEUU) s with various compositions of hard segments and soft segments of polyethylene oxide (PEO) were used as release devices. CV release from PEUUs having different initial concentrations of CV was carried out to investigate the effect of the interaction on the release profile. Faster releases of CV in an early stage were observed for PEUU loaded with a higher content of CV. Sorption experiment of CV to PEUU showed that CV was sorbed mainly to PEO segments with Freundlich profile, indicating a dual mode absorption of CV to PEUU. Thus, for the device with higher initial CV concentration, most of the CV molecules dispersed in PEUU interacted weakly so that the release occurred smoothly. In contrast, the release of CV was interfered with by the stronger interaction, when PEUU was loaded with a lower concentration of CV, resulted in a slower release rate.