Study On Sustained-release Tablet Of Torasemide

The contents of the topic are consisted in six parts: the fore five chapters regard torasemide as specific example and study the physico-chemical property,prescription and artwork,quality criteria and the preliminary pharmacokinetics of torasemide and deeply explain the common investigative regularity and method of the sustained-release and controlled-release preparation. The last chapter mainly explain the features,types,adjuvants and the vivo– vitro depen- dability of the sustained-release and controlled-release preparation and introduce the study and advancement of the sustained-release and controlled-release preparation in the last years.The research of physico-chemical property of torasemide provide the basements for the later researches; the research of prescription and artwork is the emphasis of the topic,because it determines the quality and the releasing in vivo-vitro of the preparation; the research of quality criteria can control the quality of the preparation in order to make it safety and utility;the fourth chapter can check whether the preparation achieve to extend releasing or not and whether the releasing in vitro and the absorption in vivo have the dependability or not.Some physico-chemical property of drug limit its administration route and dosage form.So it is necessary to inspect the three important physico-chemical properties:dissolubility,pKa and distribution coefficient of water/oil(Ko/w) before performulation. The methods are :to prepare buffer solutions and the standard curves of different pH, the solubility was determined with saturation method and the value of pKawas fitted with solubility curve, then the value of Ko/w was calculated with concentration ratio of torasemide in n-octyl alcohol and water phase.The researches established the foundation for the performulation.The preparation is a kind of relative-water gel-matrix tablet. The preparation which was adopted wet granulation and was used the percentage of average releasing of 12th hour,the calcium hardness of the tablets and the zero angle of granulas as evaluation indicatrix was done two orthogonal experiments,then the artwork and the prescription of the preparation was determined through synthetic comparison.The research of quality criteria include inspections of relevant substance,the assaying and the releasing in vitro. The inspection of relevant substance including the destructive tests was made with HPLC(high performance liquid chromatography); the technology of the assaying and the releasing in vitro including the linearity,constancy,reproducibility and recovery tests was made with UV-vis(ultraviolet and visible spectrophot- ometry). It is sure that the analytical methods of the preparation can control the quality of the preparation through investigating the three indicatrix.The preliminary pharmacokinetics test was done according to the 2005 Chinese Pharmacopeia in order to authenticate the feasibility of the prescription and artwork; moreover the dependability of in vivo and in vitro was inspected.