OBJECTIVE:To establish a mercury-free perchloric acid potentiometric titration method for the content determination of rocuronium bromide.METHODS:Mettler DG113-SC was used as the composite electrode.The potentiometric titration was performed with glacial acetic acid and acetic anhydride as solvents and perchloric acid(0.1 mol?L-1) as titration.The method was compared with that stated in European Pharmacopeia.RESULTS:The linear range of rocuronium bromide was 0.150 1～0.401 3 g(r=0.999 9) with an average recovery within 99.90%～99.98%.The detection limit was 1.71 mg.There was no difference between results detected by two methods.CONCLUSION:The method is simple,sensitive and accurate for the content determination of rocuronium bromide.

Objective: To establish a determination method for the related substances in josamycin and josamycin tablets by HPLC. Methods:High performance liquid chromatography was used. The column was Ultimate-AQ-C18(250 mm ×4.6 mm,5 μm), the mobile phase respectively was mobile phase A of 0. 2 mol·L-1 tetrabutylammonium hydrogen sulphate R-0. 2 mol·L-1 disodium hydrogen phosphate(pH 3. 0)-acetonitrile R-water(3∶5∶24∶68) and mobile phase B of 0. 2 mol·L-1 disodium hydrogen phosphate (pH 3. 0)-acetonitrile R-water(5∶50∶45). The flow rate was 1. 5 ml·min-1 with the detection wavelength of 232nm. The column temperature was 50℃. Results:The main component josamycin had a good separation with the other related substances. The resolution between josamycin and the related substances with the relative retention time of 1. 1-fold of josamycin was above 1. 7. The detection limit of josamycin was 1. 43ng. In josamycin raw materiel and josamycin tablets, the percentage of related substance A and B was less than 1. 5%. The percentage of related substance D was below 2. 0%. The percentage of related substance E was less than 3. 0%. The percentage of the other maximum related substances was less than 1. 0%. The percentage of all related substances was less than 12%. The percentage of related substance C was less than 1. 0% in josamycin raw materiel while 3. 0% in josamycin tablets. Conclusion:The method is accurate, sensitive and reliable in the determination of related substances in josamycin and josamycin tablets.

Objective To investigate the expression of NLRP3 in different time point of HIBD neonatal rats and to search for critical time points and alleviate HIBD dysfunction.Methods 96 newborn rats of 7 days old were randomly divided into HIBD group(n=48) and Sham operation group(n=48).HIBD model was prepared by referring to Rice method.Brain tissue was taken after 6 h,24 h,72 h,7 d.Brain injury was detected by HE stain.The expression and distribution of NLRP3 and Caspase-1 were detected by immune fluorescence and Western blot,and IL-1β and IL-18 were detected by ELISA.Results HE staining and immunofluorescence showed that NLRP3 protein (HIBD group (0.63±0.07),Sham group(0.43±0.04)) was increased significantly since 6 h in HIBD group,and its downstream protein Caspase-1,IL-1β and IL-18 were successive activated.The results showed IL-1β (HIBD group(732.28± 108.42)pg/ml,Sham group(584.58± 36.35) pg/ml) was increased significantly since 6 h in HIBD group;Caspase-1 (HIBD group(0.67±0.09),Sham group(0.30±0.05)),IL-18 (HIBD group(683.84±31.83) pg/ml,Sham group(571.32±50.91) pg/ml) was increased significantly since 24 h in HIBD group(P＜0.05).Conclusion NLRP3 and its downstream inflammatory cytokines IL-1 β and IL-18 are up-regulated when HIBD occurs.The change of NLRP3protein expression in group HIBD is earlier than changes of neuron.NLRP3 signal may mediate and participate in the occurrence and development of HIBD.