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Über dieses Produkt
- Kurzbeschreibung<p>Hot-melt extrusion with poorly soluble drugs is a challenging method to enhance the solubility. The formation of solid dispersions, specifically of glassy solid solutions, wherein the drug is dispersed on a molecular basis in an inert carrier, leads to metastable systems that have advantageous dissolution behaviour but suffer from physical stability problems. To date, there is poor understanding of the solid state structure, the mechanism by which dissolution enhancement occurs, the stability on storage and in dissolution, and the processing to solid dosage forms. The hot-melt extrusion process is influenced by several parameters. The right coordination of these parameters is decisive for the production of solid dispersions and thus, the success in solubility enhancement. The solid state and the viscosity of the extrudates can be controlled by the temperature of the barrels. Besides the configuration of the screw and the temperature profile of the barrel, the design of the die plate represents the third important extrusion parameter. By keeping the dead storage capacity at a minimum, an early solidification and thus a blockage of the dies can be prevented. Due to shear forces evolving in the extruder barrel and the ability of the drug to dissolve in the molten carrier before reaching the melting temperature, the process temperature can be kept below the melting point of the substances. Basic butylated methacrylate copolymer is a suitable carrier to enhance the solubility of the poorly water-soluble drug celecoxib in a hot-melt extrusion process. The best solubility enhancement can be obtained by dispersing the drug in the molten carrier on a molecular basis and thus, to form glassy solid solutions. The solid state characteristics of the solid dispersion can be revealed by DSC analysis and interpretation of the corresponding glass transitions. Such systems may contain a drug load of up to 60% and are stable at increased temperature and humidity which is due to the very low water uptake of the components. Glassy solid solutions of celecoxib and basic butylated methacrylate copolymer have a fast dissolution rate and result in a 58 fold supersaturated solution. The mechanism of drug release from these glassy solid solutions is carrier-controlled and governed by dissolution. The enhancement of the dissolution rate is based on improved solubility and wettability. Basic butylated methacrylate copolymer interacts chemically with celecoxib in an acid-base reaction. The hot-melt extrusion process is highly dependent on the physicochemical properties of the compounds and their miscibility in the molten state
- AutorJessica Albers
- Ausgabe1. Auflage
- VerlagCuvillier Verlag
- Seiten156 Seiten
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