Studies On Dissolution By Flow Through-cell Method

Flow through cell method is a new-style method of dissolution,has wide appliance foreground,not only in tratidional preparations but also n new preparation as bracket of drug release,suspend preparation,embedded preparation,microspheres,lipid and so on. Flow through cell method is a essential supplement to tradition dissolution method and become hotspot of dissolution research gradually overseas. From the information we can drow a conclution that there is not a systemic research to flow-through cell method and there is not a flow-through cell method calibration system .There is also a mistake in dissolution research,the mistake is to pursue high dissolution rate . In this work, the main goal is to research in the two respect. This work consisted of four production as a whole.First, using salicylic acid calibrator tablets to review releases of non-disintegrating tablets in flow-through cell dissolution method. A central composite design–response surface method was employed to select the independent variables of medium flow rate and flow mode . Model was established with dissolution of salicylic acid calibrator tablets in different time. Two order quadratic equation was best-fitted mathematic models to describe the relationship between independent and dependent variables.Bias between observed and predicted values of releases degree of select area were negligible,indicating the high predictability of the fit models.The model can be used as a calibration system of flow-through cell method.Secondly, in the foundation of having established the calibration system, enalapril maleate tablets was selected as the representative of disintegrating tablets. To select a models that correlate with the plasma drug concentrations of enalapril maleate tablets, and one compartment model was the optium one. To develop a flow- through cell method that correlate with the plasma drug concentrations of enalapril maleate tablets and compare the dissolution of enalapril maleate tablets from 5 manufacturers by this method. The results of verification test showed that the difference of different medium and manufacturers can be seen.Thirdly,.the flow through-cell dissolution method of nicotine patches was found.The results of experiments indicated that the method was simple and convinent,the results of this method was consistent with that of paddle on dish. Flow through-cell dissolution method can be used to determine the dissolution of patch.Lastly, Weibull's distribution function and others distribution function was applied to the data processing of dissolution. The results of experiments indicated that the calculating progress could be simplified tremendously and the accuracy of the treated data on drug dissolution rate was increased, when the dissolution rate and could be described by Weibull's distribution function. Weibull's distribution function could better fit the dissolution rate of rapid release prepraration in vitro.