Study On Process And Dissolution Of Ligustrazine Phosphate Tablets

The auxiliary materials of lingustrazine phosphate tablet (LPT) were studied and adjusted. Three new preparing processes were designed on the basis of preliminary test and orthogonal experiments. Lingustrazine phosphate pellets produced with new preparing processes were tested in the experiment of high temperature(60℃),high humidity(90±5%) and strong light(4500±500LXS). The results of the test proved that lingustrazine phosphate did not react with other ingredients and all the materials had good stability.The dissolutions of lingustrazine phosphate tablets (LPTs) produced with three new processes were determined and the best process was selected for pilot-scale production. According to the procedures of Chinese Pharmacopoeia in 2005, the content and dissolution of lingustrazine phosphate of the PLTs produced in pilot-scale production were checked with UV. Methodological verification was also done at the same time. Three lots of LPT (100,000 tablets/lot) were produced in pilot-scale production and the processes verification was done in the meantime. The results showed that all the quality indices of LPTs, such as appearance, content and dissolution of lingustrazine phosphate, were conformed to National Standard. The lowest average content of lingustrazine phosphate was 98% and the minimum dissolution was 93.8%. In addition, the verification of main processes in pilot-scale production indicated that both the manipulation and product quality of the new process were controllable and the new process was suitable to industrialized production.Accelerated stability test(6 months) and protracted stability test (12 months) were adopted to check the stability of LPTs produced before and after the improvement of the preparing process. To the PLTs produced with old process, no appearance change was observed during the test period but low and unstable dissolutions were recorded. Most dissolutions of those PLTs were under 80% and some of them were even under 70%. In the test of PLTs produced with new process, no appearance change was seen and all the dissolutions, both of the naked tablets and of the sugarcoating tablets, were over 89%. Moreover, the dissolution just fluctuated in a narrow range during the test.The results showed that new preparing process improved the dissolution of lingustrazine phosphate and avoided sharp decrease of dissolution of PLT in the...