Design and evaluation of temperature-responsive chitosan/hydroxypropyl cellulose blend nanospheres for sustainable flurbiprofen release.

In present work, temperature-responsive flurbiprofen (FLU) containing chitosan/hydroxypropyl cellulose (CS/HPC) blend nanospheres were prepared using emulsion method. The structures of blend nanospheres were characterized by ATR-FTIR, XRD, SEM, DSC/TGA, zeta potential and particle size analyses. Their lower critical solution temperatures (LCST) were determined and found to be 42 °C. In vitro release studies were performed in gastrointestinal-tract simulated conditions at 30 °C, 37 °C and 44 °C. As the medium temperature was increased, the release of FLU decreased, indicating that blend nanospheres had temperature-responsive feature. The FLU release demonstrated that release profiles depend upon CS/HPC ratio, amount of FLU present in the nanospheres and percentage of cross-linker used. Moreover, the cytotoxicity tests were performed via MTT method and it was observed CS/HPC nanospheres were biocompatible. Based on the in vitro release profile and cytotoxicity studies, the fabricated CS/HPC blend nanospheres could be a promising candidate as a temperature-responsive nano-carrier for controlled drug release.