A convenient preparation of 6-oligo(lactic acid)cyclomaltoheptaose as kinetically degradable derivative for controlled release of amoxicillin

6-Oligo(lactic acid)cyclomaltoheptaose (6-OLA-beta CD) with an average substitution of about 7.0 lactic acid units was prepared as a new water-soluble cyclomaltoheptaose (beta CD) derivative (solubility of about 70.7-fold that of beta CD), based on the ring-opening polymerization of 3,6-dimethyl-1,4-dioxane-2,5-dione (lactide). The product was characterized by H-1 NMR, C-13 NMR, IR, and MS spectroscopy. The complexation of amoxicillin with 6-OLA-beta CD was found to be much stronger than that with beta CD at first, and then 6-OLA-beta CD was shown to decompose moderately into beta CD and lactic acid. 6-OLA-beta CD might be greatly valuable in a controlled release system for Amoxicillin (AMX). (C) 2008 Elsevier Ltd. All rights reserved.