Preparation Of Andrographis Total Lactones Sustained-release Matrix Tablets And Studying Of Its Release Mechanism

Andrographis paniculata plays a significant role in the treatment of cardiovascular and cerebrovascular diseases. The Conventional dosage has many adverse events. To reduce the dosage of drug and the incidence of adverse reactions and improve the bioavailability,we made a sustained-release tablet for Andrographis paniculata.In the process of development of Andrographis paniculata total lactones sustained release tablet,the method to determine Andrographis total lactones is used in Prescription screening and process research,therefore, UV-visible spectrophotometry is applicated to determine total lactones content in Andrographis intermediates and tablets. And then the HPLC is used to establish the method of determination of the intermediates and indicators in the tablet which is composited by Andrographolide and dehydroandrographolide. The above two methods are simple, accurate, and able to meet the requirements of the experiment.On the basis of single factor experiment, We Select HPMC specification, the amount of filler and PVP dosage as the experimental factors. In order to select the best prescriptions,we use the Orthogonal experimental design which can help us make the best decision rapidly. The best Prescription:The optimal formulation was as follow:using20%HPMC K15M as retardants, starch and lactose(3:1) as fillers,3%PVP as porogens.In the process of studying the quality standards of the matrix tablets, We use the rotating basket to determinate the release of total lactones Andrographis. The UV-visible spectrophotometry is used to determine the Andrographis total lactones content.And the HPLC is to determine the content of andrographolide and dehydroandrographolide. At the same time routine examination about tablet has been made for the Andrographis total lactones hydrophilic matrix tablets. The results show that the quality of the tablet is stable and controllable.We investigate the mechanism of drug release matrix tablets by studying the dissolution and release process of the different amount of HPMC matrix tablets, and its release kinetics equation. The results show that when HPMC content below15%, the sustained release tablets showed the release mechanism is diffusion and dissolution.When the HPMC content is more than15%, the performance of the mechanism is dissolution. On the basis of this research, we established a mathematical model for the sustained release tablets which can describe the dissolution and release process of it.