Synthesis of dual responsive cyclotriphosphazene‐based IPN hydrogels for controlled release of chemotherapeutic agent

Dual responsive cyclotriphosphazene (CTP)‐based hydrogels have been synthesized for a controlled release of FU, a hydrophilic drugs. These hydrogels composed of mono (methacryloyl‐2‐ethoxy)‐pentakis(N¹,N¹‐dimethylpropane‐1,3‐diamino)‐cyclotriphosphazene (HEMA (DMPDA)₅CP), acryl amide and pectin were synthesized by free radical polymerization method using methylenebisacrylamide cross linker. The CTP hydrogels were characterized to understand the structure, drug nature in the network and morphology by FTIR, DSC, XRD and SEM, respectively. In this paper, the swelling (dynamic and equilibrium) properties of cyclotriphosphazene hydrogels were investigated, showing dual (pH and thermo) responsiveness and large variation in the swelling capacity. Based on these results the structural parameters of the hydrogel networks such as the average molecular weight between cross‐links (M_c) and polymer–solvent interaction parameter (χ) were determined. The CTP hydrogels has high FU loading efficiency 65 ± 0.5. In‐vitro FU release of these hydrogels was controlled for about 24 hr also hydrogel showed a distinct initial burst. The CTP hydrogels are bearing both hydrophilic groups of pectin and hydrophobic groups of CTP exhibited dual responsive behaviors with pH and temperature. Copyright © 2015 John Wiley & Sons, Ltd.