beta-Cyclodextrin conjugates for the intestinal delivery of p-aminobenzoic acid: synthesis, and in vitro assessment

摘要

A controlled drug delivery system using the conjugation of p-aminobenzoic acid (PABA) to beta-cyclodextrin was developed for intestinal delivery. PABA was covalently conjugated to the primary C-6 hydroxyl group of beta-cyclodextrin through ester linkage, and the preliminary release characteristics of PABA in rat gastrointestinal tract fluids were investigated at 37 degrees C within 24 h. In the fluids of stomach, the conjugates did hardly release PABA, and released PABA significantly up to 78.6 % in the fluids of intestine, respectively. These results indicate that the conjugate activation took place site-specifically in the rat intestinal fluids. Moreover, the drug release curves demonstrate that PABA could be gradually released in a long time with low initial burst release amount.