Abstract: The encapsulation of “micelles-enhanced” polyelectrolyte capsules to Rhodamine B, a positively charged small molecule, and in vitro release behavior of Rhodamine B containing capsules, were studied. Studies on the encapsulation kinetics and loading amount of capsules to water-soluble Rhodamine B suggest that water-soluble substances can be efficiently entraped into this type of “micelles-enhanced” polyelectrolyte capsules. In vitro release tests suggest that there were difference in release behavior between Rhodamine B-containing capsules that performed in release media with various pH values. However, for these release profiles, a similar trend was displayed, and the whole release curves have several periods with different Rhodamine B release rates, which include a burst release, a lag period, a rapid release phase and a sustained release stage. The burst release in the first stage was significant, which should be ameliorated in the following study. Simultaneously, ion strength seemed to have no significant effect on the release behavior of Rhodamine B-loaded capsules.

Key words: LbL technique, Polyelectrolyte capsule, Micelle enhancement, High efficient encapsulation, Release profile