Study Of Levodopa And Benserazide Tablets

Levodopa and Benserazide Tablet is a compound preparation consisting of dopa decarboxylase inhibitor benserazide hydrochloride and levodopa?1:4,w/w?,with a specification of 50/200 mg,and a trade name of Madopar,originally developed by Shanghai Roche Pharmaceutical Co.,Ltd.Benserazide hydrochloride and levodopa have a good quality of compression,but benserazide hydrochloride is easy to hydrolyze.So how to obtain the in vitro dissolution curve is consistent with the original development agent,at the same time improve the stability of benserazide hydrochloride is the difficulty and the key point of this paper.In this study we take Madopar as the reference preparation,and on the basis of the analysis of the reference preparation,conducts the research on the formulation and process,quality standard and stability of the levodopa and benserazide tablet.And we discuss the possible mechanism of tablet microenvironment p H regulator and moisture improving the stability of benserazide.With the in vitro dissolution curve as the index,the disintegrant type,amount and addition method,and the binder type and amount are investigated.The results show that with 4%crospovidone?type A?disintegrant and 3%pregelatinized starch?type B?binder adding to the preparation,the levodopa and benserazide tablet has the highest in vitro dissolution curve similarity to the original reference preparation?f₂=75?.Further research on the micro-environmental p H adjuster,filler and moisture of levodopa and benserazide tablet show that using anhydrous calcium hydrogen phosphate of type C as a filler and 1% tartaric acid was added as the p H adjuster,and the tablet moisture was controlled to be less than 1%,can effectively inhibit the hydrolyze of benserazide to obtain tables with good in vitro dissolution and stability.At the same time the method of identification,content determination,dissolution determination and related substance determination of levodopa and benserazide tablet is verified by the method.The results show that the verification indexes and so on all meet the requirements.The established quality standard can be used for levodopa and benserazide tablet.The influencing factors and stability test results show that the levodopa and benserazide tablet is sensitive to humidity,and benserazide is easy to hydrolyze;the stability effect caused by high temperature and light is opposite.In the end,the study obtained levodopa and benserazide tablets with high in vitro dissolution profile similarity,good stability and controllable quality.