ABSTRACT
Objective:To establish an HPLC method for the determination of methylthioninium chloride injection and its related substances. Methods:Octadecylsilane bonded silica was used as the filler. A Waters Symmetry C18 column (150 mm × 4. 6 mm, 5μm) was used with the mobile phase of 0. 3% phosphoric acid solution-acetonitrile (70∶ 30). The detection wavelength was 246 nm and the column temperature was 30℃. The flow rate was 1. 0 ml·min-1 and the injection volume was 10μl. Results:The separation degree of methylthioninium chloride peak and impurity peaks was good. Methylthioninium chloride within the range of 2. 0-60. 0 μg· ml-1showed a good linear relationship (r=0. 9998). Impurity A within the range of 0. 2-3. 2 μg·ml-1 showed a good linear relation-ship (r=0. 999 6). The average recovery of methylthioninium chloride was 99. 75% and RSD was 0. 86% (n=9). Conclusion:The method is simple, accurate and specific with high precision. It can be used to determine the content of methylthioninium chloride injec-tion and its related substances.
ABSTRACT
OBJECTIVE:To improve the method for the determination of content and related substances of Molsidomine tablet. METHODS:HPLC was adopted to determine the content and related substances,HPLC-MS was adopted for the qualitative degra-dation impurities in destruction test. The column was Waters Symmetry-C18 with mobile phase of 0.05% formic acid- methanol (gradient elution) at a flow rate 1.0 ml/min and 0.2 ml/min (respectively for content and related substances determination,mass spectrometry),the detection wavelength was 210 nm,column temperature was 30℃,the injection volume was 20μl and 5μl(re-spectively for content and related substances determination,mass spectrometry). RESULTS:Each component was well separated un-der chromatographic conditions;degradation impurities were confirmed;the linear range of molsidomine was 4. 0-28.0 μg/ml(r=0.9997);RSDs of precision,stability and reproducibility tests were lower than 1%;recovery was 97.74%-100.70%(RSD=0.49%,n=9). CONCLUSIONS:The method is simple,accurate with good specific and high precision,and can improve the quali-ty control of Molsidomine tablet.
ABSTRACT
Pancreas of 53 aborted fetuses ranging from 5 to 41 weeks were fixed in Bouin's fluid and embedded in paraffin, and the sections were stained with Alcian bluephloxine and Grimelius silver technique. The A, B and D cell of islet of Langerhans were demonstrated with immunohistochemical PAP method also. 14 pancreas among them were fixed in 2% glutaraldehyde and embedded in Epon 812, and observed with TEM. Typical A, B and D islet cells were observed with LM at 12 weeks of fetal age. Undifferentiated, differentiated and degenerated cells were distinguished in the pancreatic islets at 14 to 41 weeks of fetal age. The secretory granules of the exoerine cells were observed after 14 weeks of fetal age. The functional differentiation of endocrine cells precede that of exocrine cells. The morphometrical measurement testified that the endocrine portion of fetal pancreas was obviously larger than that of adult. This study provides some morphological data for the pancreas transplantation in clinical medicine.