Purpose To prepare the sustained-release tablet of tetramethylpyrazine phosphate with hydroxypropylmethylcelluose(HPMC) as matrix material. MethodsThe paddle method and the HPLC method were erspectively used determined the cumulative drug released in vitro and the serum concentration in vivo.ResultsThe cumulative drug released in the first hour was about 20%, while in 12 hours it was above 85%. Drug release behavior can be best described by Higuchi equation, and the release rate decreased as the viscosity and/or the amount of HPMC increased. Compared with the market tablet on the rabbits, the sustained release tablet had the decreased peak concentration (P < 0.05 ); the prolonged peak time and mean residence time (P< 0.05).ConclusionsThe matrix tablet was a good sustained-release dosage form and it had a good in vitro-in vivo correlation.

Objective To explore the diagnostic significance of CT and MRI in dermatofibrosarcoma protuberans.Methods Analyze the CT and MRI images of 16 cases which were confirmed as dermatofibrosarcoma protuberans by pathology.The medical imaging features of dermatofibrosarcoma protuberans were summarized.In the total 16 cases(including 6 male cases,10 female cases),15 cases had suffered from dermatofibrosarcoma protuberans for more than 1 year, 11 cases for more than 5 years, and 9 cases had history of recurrence.Results On MRI, the mass was slightly hypointense on T 1 WI, inhomogeneously hyperintense on T 2 WI with inhomogenous enhancement.The diameters of mass were less than 5 cm in 3 cases,and were more than 5cm in 13 cases.Fifteen cases had clear demarcation between the masses and their adjacent muscles , 7 cases had “suspension sign” in shapes, 10 cases had “sub-nodules outward” features at the edge of the tumors , 12 cases had “multinodular” features inside the tumor , and 8 tumors grew into the surrounding fat layer like roots.Conclusion Dermatofibrosarcoma protuberans can be diagnosed accurately based on the features displayed on CT and MRI.