Résumé
OBJECTIVE: To compare and optimize the analytical methods for detection of related substances of etimicin sulfate injection. METHODS: For the HPLC-CAD (charge aerosol detector)method, the mobile phase was 0.2 mol·L-1 trifluoroacetic acid aqueous solution-methanol (95:5), the flow rate was 1.0 mL·min-1 and the column temperature was maintained at 30℃. The nebulization temperature for the CAD was maintained at 30℃ and the gas pressure was 0.24 MPa.The HPLC-ELSD and HPLC-PAD methods adopted by the Ch.P 2015 were also used to detect the related substances of etimicin sulfate injection for the purpose of comparison. RESULTS: Compared with the HPLC-ELSD method, the HPLC-CAD method showed higher selectivity and sensitivity; compared with the HPLC-PAD method, the results of the determination of the impurities were more accurate for the HPLC-CAD method. CONCLUSION: The separation capability of the new HPLC-CAD method for detection of the related substances of etimicin sulfate injection is superior to HPLC-PAD and HPLC-ELSD methods and can detect more impurities, which is suitable for the quality control of etimicin sulfate injection.
Résumé
OBJECTIVE: To establish an ion chromatography method for measuring the content of sodium sulfite as an antioxidant in etimicin sulfate injection. METHODS: DionexIonPac AS11-HC (4 mm×250 mm) and DionexIonPac AG1-HC (4 mm×50 mm) were employed as anion analytical column and anion guard column to separate sodium sulfite and determine its content. Gradient elution was carried out with potassium hydroxide solution at the flow rate of 1.0 mL·min-1. Conductivity detector was used with the suppressor current set at 99 mA, the conductivity pool was maintained at 35℃ and the column temperature was maintained at 30℃. RESULTS: A good linear relationship was found between the peak response and the concentration range of 8-80 μg·mL-1. The detection limit was determined to be 0.02 μg·mL-1 (S/N=3), and the quantitation limit was 0.09 μg·mL-1 (S/N=10). CONCLUSION: In this paper, we set up an analytical technique with such characteristics as rapidity, accuracy and reproducibility, which will serve to control the dosage of sodium sulfite. So far, it seems appropriate to use sodium sulfite as an antioxidant, but its amount in pharmaceutical preparations should be further optimized and decreased in the future.