Effect of Temperature on Physicochemical Properties of Plasticized Hydroxypropyl Methylcellulose K100–Carbopol 934 Films Containing Propylene Glycol as Plasticizer

This paper studies the effect of different temperatures on different important physicochemical characteristics of plasti-cized hydroxypropyl methylcellulose (HPMC) K100-Carbopol 934 films containing propylene glycol (as a plasticizer), such as the rheology, thickness, folding endurance, tensile strength, elongation, and in vitro swelling with diffusion ki-netics. Rheology of HPMC K100-Carbopol 934 blend dispersions containing propylene glycol (before film casting) demonstrates that the flow is shear thinning and pseudoplastic. In the study of in vitro swelling, the relaxation-controlled transport is the predominant process of solvent diffusion into these plasticized HPMC K100–Carbopol 934 blend films under study. The results suggest that the solvent transport process followed second-order kinetics, and the diffusion mechanism is non-Fickian diffusion. Regular measurements of mass variation, as well as the isothermal ki-netic curves, are plotted. The plasticized HPMC K100–Carbopol 934 blend films are characterized by differential scanning calorimetry and scanning electron microscopy.