A Ph-Sensitive Drug Carrier Based on Maleic Acid-Substituted Cyclotriphosphazene

GRAPHICAL ABSTRACT

Abstract

The cyclotriphosphazene derivative N₃P₃[OC₆H₄-p-CH₂O(CO)CH˭CH(CO)OH]₆ bearing maleic acid groups was synthesized and characterized by NMR, FTIR spectroscopy, and MS. A cross-linked network was produced by free radical copolymerization of this phosphazene derivative with N-vinyl-2-pyrrolidone (NVP). Swelling experiments indicated that the cross-linked network was highly sensitive to pH environments. In vitro release studies have been performed in 2.0 and 7.4 pH media to simulate gastric and intestinal conditions. The results indicated a dependence on the pH of the release media and extent of crosslinking.

Keywords:

• Cyclotriphosphazene
• pH-controlled release
• cross-linker
• swelling
• maleic acid