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Dual crosslinked pH‐ and temperature‐sensitive hydrogel beads for intestine‐targeted controlled release
Author(s) -
Ma Liwei,
Liu Mingzhu,
Liu Hongliang,
Chen Jun,
Gao Chunmei,
Cui Dapeng
Publication year - 2010
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1434
Subject(s) - materials science , swelling , differential scanning calorimetry , chitosan , fourier transform infrared spectroscopy , scanning electron microscope , ionic strength , controlled release , copolymer , chemical engineering , grafting , self healing hydrogels , polymer chemistry , nuclear chemistry , chemistry , polymer , nanotechnology , aqueous solution , composite material , organic chemistry , physics , engineering , thermodynamics
Novel drug‐loaded hydrogel beads for intestine‐targeted controlled release were developed by using pH‐ and temperature‐sensitive carboxymethyl chitosan‐graft‐poly( N , N ‐diethylacrylamide) (CMCTS‐g‐PDEA) hydrogel as carriers and vitamin B 2 (VB 2 ) as a model drug. The hydrogel beads were prepared based on Ca 2+ ionic crosslinking in acidic solution and formed dual crosslinked network structure. The structure of hydrogel and morphology of drug‐loaded beads were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The study about swelling characteristics of hydrogel beads indicated that the beads had obvious pH‐ and temperature‐sensitivity. In vitro release studies of drug‐loaded beads were carried out in pH 1.2 HCl buffer solution and pH 7.4 phosphate buffer solution at 37°C, respectively. The results indicated that the dual crosslinked method could effectively control the drug release rate under gastrointestinal tract (GIT) conditions, which was superior to traditional single crosslinked beads. In addition, the effects of grafting percentage, pH value, and temperature on the release behavior of the VB 2 were investigated. The drug release mechanism of CMCTS‐g‐PDEA drug‐loaded beads was analyzed by Peppa's potential equation. According to this study, the dual crosslinked hydrogel beads based on CMCTS‐g‐PDEA could serve as suitable candidate for drug site‐specific carrier in intestine. Copyright © 2009 John Wiley & Sons, Ltd.