Insulin-loaded hydroxypropyl methyl cellulose-co-polyacrylamide-co-methacrylic acid hydrogels used as rectal suppositories to regulate the blood glucose of diabetic rats

The purpose of this study was developing a novel hydroxypropyl methyl cellulose- co -polyacrylamide- co -methacrylic acid (HPMC- co -PAM- co -PMAA) hydrogel, which was used as rectal suppository to regulate the blood glucose of diabetes. HPMC- co -PAM- co -PMAA hydrogel was fabricated via free-radical polymerization. Fourier transform infrared spectroscopy (FTIR) and Raman spectra were used to confirm the fabrication of HPMC- co -PAM- co -PMAA hydrogel. Their inner morphology was observed with scanning electron microscope (SEM). The extracts of hydrogel were applied to study their cell viability . The hypoglycemic effects of insulin (INS)-loaded HPMC- co -PAM- co -PMAA hydrogels were investigated by rectal administration. FTIR and Raman spectra confirmed the obtaining of HPMC- co -PAM- co -PMAA hydrogels. Many micro-pores were found in the SEM photograph of HPMC- co -PAM- co -PMAA hydrogels. Cell experiments indicated that HPMC- co -PAM- co -PMAA hydrogel was out of cytotoxicity. In vitro release profiles showed that INS-loaded hydrogel could release INS at a continuous manner in pH 7.4 buffer (rectal conditions). Animal experiments suggested that INS-loaded hydrogel had an obvious hypoglycemic effect. Therefore, as a convenient and economic method of administration, INS-loaded HPMC- co -PAM- co -PMAA hydrogels could be used as rectal suppositories to regulate blood glucose.