The in vitro evaluation of ‘azo containing polysaccharide gels’ for colon delivery
| Autor: | Guy Van den Mooter, B Maris, Barbara Stubbe, Joseph Demeester, Stefaan C. De Smedt |
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| Rok vydání: | 2001 |
| Předmět: |
Male
Colon Inulin Pharmaceutical Science In Vitro Techniques chemistry.chemical_compound Drug Delivery Systems Polysaccharides medicine Animals Organic chemistry Rats Wistar Inulinase Cecum Dextranase Azo compound Hydrolysis Dextrans Rats Dextran chemistry Self-healing hydrogels Flavin-Adenine Dinucleotide Swelling medicine.symptom Drug carrier Azo Compounds Gels Algorithms NADP Nuclear chemistry |
| Zdroj: | Journal of Controlled Release. 75:103-114 |
| ISSN: | 0168-3659 |
| Popis: | This study reports on 'azo-polysaccharide gels', more specifically azo-inulin and azo-dextran gels, for colon drug delivery. Compared with azo-hydrogels which can be only degraded by reduction of the azo-groups, this study evaluates whether, in vitro, azo-polysaccharide gels can be degraded through both reduction of the azo-groups in the crosslinks as well as enzymatic break down of the polysaccharide backbone. The azo-polysaccharide gels were synthesized by radical crosslinking of a mixture of methacrylated inulin or methacrylated dextran and N,N'-bis(methacryloylamino)azobenzene (B(MA)AB) and were characterized by dynamic mechanical analysis and swelling measurements. Azo-dextran gels could be obtained from methacrylated dextran having low degree of substitution but not from lowly substituted methacrylated inulin. Increasing the amount of B(MA)AB resulted in denser azo-inulin and azo-dextran networks. Compared with their swelling in dimethylformamide, all azo-dextran gels became more swollen in water while azo-inulin gels shrank upon exposure to water, indicating a more hydrophobic character of the azo-inulin gels. Break down of the inulin and dextran chains in the azo-polysaccharide gels by inulinase and dextranase, respectively, was observed. However, the degradation of azo-dextran gels by dextranase seemed to be more pronounced than the degradation of the azo-inulin gels by inulinase. In rat caecal content medium, reduction of the azo function in azo-inulin gels was not observed. This may be attributed to a low partitioning of nicotinamide-adenine dinucleotide phosphate (NADP(+)) in the gels. |
| Databáze: | OpenAIRE |
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