Modeling of Thermal Gelation and Degelation of MC and HPMC Hydrogels

Hydrogels play a key role in many pharmaceutical and bio-applications. It is therefore advantageous to be able to predict the gelation process so that properties and performance of hydrogels can be optimized for these applications. This study examines the numerical models proposed earlier and modifies them in order to describe more accurately and appropriately the thermally induced gelation and degelation of methylcellulose (MC) and hydroxypropyl methylcellulose (HPMC) systems. In this work, variations of a bell-shaped mathematical formulation are used to fit the differential scanning calorimeter (DSC) heating and cooling data for MC and HPMC hydrogels. One of the models developed, referred to as C_p1 + C_p2 - C_p3 model, could provide consistently accurate curve fit for all concentrations of MC and HPMC hydrogels. These results are further used to predict the enthalpy-based degree of gelation and degelation as a function of temperature for various concentrations of MC and HPMC.