Synthesis and characterization of cetirizine-containing, pH-sensitive acrylic acid/poly(vinyl alcohol) hydrogels.

ABSTRACT In this study, interpenetrated acrylic acid (AA)/poly(vinyl alcohol) (PVA) hydrogels were prepared by free-radical polymerization with N,N-methylene bisacrylamide (MBAAm) as a crosslinker. The basic structural parameters, such as the molecular weight between crosslinks, volume interaction parameter, number of crosslinks, Flory-Huggins solvent interaction parameter, and diffusion coefficient, were calculated. Cetirizine dihydrochloride was loaded as a model drug in selected samples. The prepared hydrogels were evaluated for swelling, sol-gel fraction, and porosity. The swelling of the AA/PVA hydrogels was found to be directly proportional to the pH, that is, 1.2-7.5, depending on composition. The percentage of cetirizine hydrochloride was found to be directly proportional to the buffer pH and was at its maximum at pH 7.5, that is, 90-95%, and its lowest at pH 1.2, that is, 20-30%. The gel fraction increased with increasing concentration of AA and MBAAm, whereas the porosity showed the same response with AA, but an inverse relationship was observed with MBAAm. The drug-release data were fitted into various kinetics models, including the zero-order, first-order, Higuchi, and Peppas models, which showed non-Fickian diffusion. The prepared hydrogels were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy, and no interaction was found among the polymer ratio and the drug. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43407. [ABSTRACT FROM AUTHOR]