Research Of The Calcium Alginate-chitosan Intra-gastric Floating Beads

TO prepare calcium alginate-chitosan intra-gastric floating beads with favorable floatability, we use sodium alginate solution as base material, chitosan-calcium chloride solution as fixative solution. Then combining with the solid dispersion method and investigate the in vitro drug release property of the beads.Part 1 Research of Floating Characteristics of the Calcium Alginate-chitosan Intra-gastric Floating Beads. Sodium alginate solution added with frother was slowly dripped into chitosan-calcium chloride solution added with acetic acid; calcium alginate-chitosan intra-gastric floating beads were obtained after drying. The effects of frother, addition amount of acetic acid,the concentration of alginate solution,chitosan and calcium chloride solution on the floating characteristics of beads were investigated. Frother and addition amount of acetic acid were the main influence factors of the floating characteristics while the concentration of alginate solution,chitosan and calcium chloride solution also had some influences.Part 2 Study on the calcium alginate-chitosan intra-gastric floating beads with drugs. DIP and NAR were used as model drugs. The solid dispersion of these two drugs was prepared by the combined carrier of the Polyacrylic Resinâ…¡(PRâ…¡), Eudragit RLPO or both of them. Sodium alginate solution mixed with the powder of the solid dispersion of drug and frother was slowly dripped into chitosan-calcium chloride solution added with acetic acid. Calcium alginate-chitosan intra-gastric floating beads of DIP&NAR were obtained after drying. The effects of solid dispersion on in vitro release of the drugs were investigated.Part 3 Study of the Calcium Alginate-chitosan Intra-gastric Floating Beads in vivo floating characteristics and drug release property. Barium sulfate was encapsulated in the floating beads as contrast agent, we use the X-ray photography after feeding beads, and detected stranded showing bright spots in beagle dog's stomach, lasted about 7 h. we use three beagle dogs for their own control, and fed them sustained-release DIP floating beads and common tablet. At the set time points blood in the foreleg was draw and using high performance liquid chromatography (HPLC) to determination the blood concentration, compared sustained-release floating beads and common tablet in pharmacokinetic.In this experiment, sodium alginate crosslink with divalent calcium ions and become insoluble gel matrix of the beads, alginate - Chitosan Floating beads with good floating properties was prepared, the preparation process was under mild conditions, no organic solvent was used, it is a good multi-unit gastric floating drug delivery system. Combination with the solid dispersion, using Polyacrylic Resinâ…¡(PRâ…¡), Eudragit RLPO alone or in combination carrier, and made two different drugs show some ability of sustained release, and achieve floating in the body, it provide some ideas for the development of new multi-unit floating drug delivery system.