Controlled Release of Perillyl Alcohol via pH-Responsive Chitosan-Polypyrrole Nanocarriers

This work focused on developing CS/PPy, a pH-responsive controlled-release nanocarrier composed of natural polymer, the chitosan (CS), and synthetic polymer, the polypyrrole (PPy). The goal was to evaluate its potential application in controlled release studies of perillyl alcohol (POH). To enhance its properties, CS/PPy was cross-linked with glutaraldehyde, resulting in a new material, CS/PPy/GA. CS/PPy and CS/PPy/GA demonstrated high encapsulation efficiency for POH. The release of POH was investigated at pH 4.5, 6.0, and 7.4. The POH release rate exhibited pH-dependent behavior, with a significantly higher release observed in acidic media (pH 4.5) compared to neutral/basic media (pH 7.4). This suggests the potential for controlled release of POH in response to specific physiological environments. The Korsmeyer-Peppas model was followed for the release of POH from CS/PPy at all pH values that were studied. The release behavior of POH from CS/PPy/GA exhibited a pH-dependent mechanism. The Korsmeyer-Peppas model best described release at pH 4.5 and 6.0, while the Higuchi model provided a better fit at pH 7.4. The results suggested that the synthesized materials exhibited high affinity for POH, and the release behavior is pH-dependent.