Preparation and properties of a pH/temperature-responsive carboxymethyl chitosan/poly(N-isopropylacrylamide)semi-IPN hydrogel for oral delivery of drugs.
Thermo- and pH-responsive semi-IPN polyampholyte hydrogels were prepared by using carboxymethylchitosan and poly(N-isopropylacrylamide) with N,N'-methylenebisacrylamide (BIS) as the crosslinking agent. The swelling characteristics of these hydrogels at distinct compositions as a function of pH and temperature were investigated. It was found that the semi-IPN hydrogels demonstrated the pH- and temperature-responsive nature of the materials, and it also showed good reversibility. The study on the release of coenzyme A (CoA) showed that within 24h the cumulative release ratio of CoA was 22.6% in pH 2.1 solution and 89.1% in pH 7.4 solution at 37 degrees C, respectively. The release rate of CoA was higher at 37 degrees C than 25 degrees C in a pH 7.4 buffer solution. An increased release rate of CoA was observed with the content of carboxymethylchitosan increasing in the hydrogel at 25 degrees C in pH 7.4 solution. These results show that semi-IPN hydrogel seems to be of great promise in pH-temperature oral drug delivery systems.
Guo
Bao-Lin
BL
Institute of Fine Chemical and Engineering, Henan University, Kaifeng, Henan 475001, People's Republic of China.
Gao
Qing-Yu
QY
D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D000284:Administration, Oral; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000031:analogs & derivatives* / Q000737:chemistry; D003065:Coenzyme A / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D011108:Polymers / Q000737:chemistry*; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
D000178:Acrylamides; D000180:Acrylic Resins; D020100:Hydrogels; D011108:Polymers; C514968:carboxymethyl-chitosan; C052970:poly-N-isopropylacrylamide; D048271:Chitosan; D003065:Coenzyme A