OBJECTIVE:To provide reference for the understanding of quality status of Insulin injection and improvement of related standards. METHODS:The statutory methods of Insulin injection were adopted to test 32 batches of samples(including ap-pearance,identification,capacity,visible foreign matter,sterility and potency determination of biological method). Consulting specification of other similar products,RP-HPLC was conducted to determine the related impurities,content and phenol in sam-ples;HPSEC was conducted to determine the high molecular weight proteins and atomic absorption spectrophotometry was conduct-ed to determine the Zn content. RESULTS:Results of all the 32 batches of samples were qualified by the test of statutory methods. According to the method of other similar products,the determination result of A21 desamido insulin was 15.6%-39.2% and general-ly greater than 5.0%, which was the highest limit of similar products;insulin was 93.2%-102.7%;protein polymer was 0.5%-0.6%;phenol was 2.34-2.51 mg/ml and Zn was 12.3-14.8 μg/100 U. CONCLUSIONS:The statutory specification of Insulin injection is short of many key specification items such as impurities and content determination;the contents of protein polymer, phenol and Zn were in good control;the contents of A21 desamido insulin are generally high,and stability of insulin main peak is relatively poor.

BACKGROUND:There is currently no anatomic locking plate suitable for the anteromedial platform,so the medial locking plate of the tibial plateau is usually placed forward to fix anteromedial compression fractures caused by hyperextension varus injury.Due to the inability of the locking screw to achieve vertical fixation of the fracture line,coupled with the influence of the patellar ligament,the clinical results are still unsatisfactory. OBJECTIVE:To compare the biomechanical performance of a new type of plate with traditional internal fixation methods in treating hyperextension varus tibial plateau fractures through finite element analysis. METHODS:CT data of 20 cases of hyperextension varus tibial plateau fractures were collected,and their morphological characteristics,such as medial posterior tibial slope,the medial articular fracture angle,surface area,and anterior cortical height were measured.A 24-year-old male volunteer with a height of 175 cm and a weight of 65 kg was selected,and his tibial CT data were imported into Mimics 21.0 software to generate a 3D model.Then,internal fixation models were imported into SolidWorks 2017 software.New type of plate,medial locking plate,posterior medial locking plate,and 6.5 mm hollow screws fixed data models were established based on the measured morphological data.Ansys 17.0 software was used to load stress on the four fixation models and compare their biomechanical performance. RESULTS AND CONCLUSION:(1)With the increase of axial load,the peak stresses of different internal fixation models approximately increased proportionally.At 500 N,the peak stress values were as follows:screw group(6.973 7 MPa)