Rheological and drug-release behaviour of a scleroglucan gel matrix at different drug loadings
The aim of this study was to investigate the drug-loading effects on release and mechanical properties of a scleroglucan gel, with the intention of considering them in delivery systems formulations. The rheological and kinetic properties of a 2% w/w scleroglucan gel matrix loaded and 0, 0.02, 0.04,...
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| Autores principales: | , , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_09598103_v54_n12_p1613_Francois |
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| Sumario: | The aim of this study was to investigate the drug-loading effects on release and mechanical properties of a scleroglucan gel, with the intention of considering them in delivery systems formulations. The rheological and kinetic properties of a 2% w/w scleroglucan gel matrix loaded and 0, 0.02, 0.04, 0.06, 0.2 0.4% w/w of theophylline (Th, used as a model drug) were investigated. Rheological measurements were performed in a controlled-stress rotational-shear rheometer under isothermal conditions. For theophylline release from the gel a flat Franz cell was used and the kinetic parameters were derived applying a semi-empirical power law. The influence of scleroglucan molar weight on kinetic and rheological behaviour was also studied. Results suggest two possible effects of drug loading on the gel network: in the 0.04-0.06% w/ w Th range a plasticizing effect and in the 0.2-0.4% w/w Th range a rigidization effect. In the first range mentioned, the changes in the gel structural properties tested by means of rheological measurements are coincident with changes in drug-release kinetics. © 2005 Society of Chemical Industry. |
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