초록 |
A novel drug delivery system consisting of poly(vinyl alcohol) (PVA)/poly(N-isopropylacrylamide) (PNIPAAm) hydrogel microspheres and poly(vinyl alcohol) (PVA)/poly (acrylic acid) hydrogel matrix was prepared by incorporating various amounts of PVA/PNIPAAm microspheres for the prolonged and sustained release. The morphology of both pH-sensitive and temperature-sensitive hydrogels was examined by scanning electron microscope. The coomassie brilliant blue, which was used as a model drug, was loaded in PNIPAAm/PVA microspheres. The released amounts of coomassie brilliant blue were measured by UV/VIS spectrophotometer at 581nm. The release characteristics were studied at several different temperatures (4, 25, 40 °C) and pH’s (2, 7, 10). Both temperature-sensitive microsphere and pH-sensitive matrix played important roles in controlling the release of drug depending on the external stimuli. |