Ho-Jeong Ahn

Preparation and Characterization of Triclosan-Containing Microcapsules by Complex Coacervation

Microcapsules were prepared by complex coacervation between gelatin (Type A) and carboxymethylcellulose (CMC). Triclosan (TS) dissolved in octyl salicylate (OS) was used a core material and glutaraldehyde as a crosslinking agent. The microcapsules on the scanning electron micrographs were spherical and exhibited core and shell morphology. The thermograms of freeze-dried microcapsules showed no evidence for the melting of TS, suggesting that TS remained dissolved in the cores of the microcapsules and did not exist as a crystalline solid even after the microcapsules were dried. Microelectrophoresis revealed that the point of zero charge of the microcapsules occured around pH 3.3, far below the isoelectric point of gelatin. This means that along with gelatin, CMC, a negatively charged polymer, constitutes the wall of microcapsules, decreasing the positive charges on the gelatin. The degree of release of TS and OS from the microcapsules in ethanol/water solvents was strongly dependent on the content of the alcohol, a good solvent for the core materials. No significant release was observed in ethanol/water (1/3, v/v) but the release was significant when the content of the alcohol increased.