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OBJECTIVE: To establish an improved reversed-phase high performance liquid chromatography method coupled with pulsed electrochemical detection for determining the related substances of netilmicin sulfate injection. METHODS: Agilent Proshell 120 SB-C18 column (4.6 mm×150 mm, 2.7 μm)and gradient elution were used. Mobile phase A was 0.2 mol·L-1 trifluoroacetic acid in 0.1 mol·L-1 sodium hydroxide solution-acetonitrile (97:3), mobile phase B was 0.1% pentafluoropropionic acid-acetonitrile (97:3), and the flow rate was 0.8 mL·min-1. A pulsed electrochemical detector was adopted, and the temperatures of detector and column were kept at 35℃. The working electrode was a gold electrode with diameter of 3 mm and a quadruple-potential waveform (QPW)was selected as detection waveform. The injection volume was 25 μL. NaOH solution of 0.8 mol·L-1 was added post-column at a flow rate of 0.3 mL·min-1. RESULTS: A total of 28 impurities could be detected and effective separation was achieved in the typical sample and most of which could not be separated in the method of Ch.P 2015. The linearity of the calibration curve for netilmicin ranged from 0.25 to 15 μg·mL-1 with a coefficient of determination equal to 0.999 1. The LOD and LOQ of netilmicin were found to be 0.25 ng and 1.25 ng, respectively. The repeatability RSD(n=6) of the single largest impurity and total impurities were 0.9% and 0.8%, respectively. The sample solution was stable within 24 h. CONCLUSION: Compared with previously published investigations, the improved method shows higher sensitivity, better separation ability and good reproducibility, especially for differentiating the origin of bulk drug for netilmicin sulfate injection, thus is more suitable for the determination of related substances of netilmicin sulfate injection.
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Objective To investigate the preventive effect of octreotide combined with netilmicin sulfate on postoperative infection in suppurative appendicitis and its effect on helper T cell 17(Th17)/regulatory T cells(Treg)imbalance.Methods 148 patients with acute suppurative appendicitis in Xiangshan Hospital of Traditional Chinese Medicine from August 2014 to May 2016 were randomly divided into observation group(n=74)and control group(n=74).All were underwent laparoscopic appendectomy surgery,the control group took netilmicin sulfate combined with ornidazole for anti-infection after operative,while the observation group added octreotide acetate subcutaneously.The levels of serum interleukin(IL)-4,IL-6,IL-10,IL-17,IL-23,transforming growth factor β(TGF-β),interferon γ(IFN-γ)and Th17,Treg cell ratio and expression levels of related transcription factorbefore and after treatment were detected,Th17/Treg change were analyzed.Results The levels of IL-4,IL-6,IL-10,IL-17,TGF-β were decreased,IFN-γ were increased after treatment(P<0.01),the improvement of those indicators in the observation group were supior than control group(P<0.05).Th17,Treg cell ratio and expression levels of related transcription factor orphan nuclear receptorγt(RORγt),Forkhead box protein P3(Foxp3)were decrease,Th17/Treg was reduced after treatment(P<0.01),those indexes in observation group were lower than those in control group(P<0.05).The wound infection,intra-abdominal infections and other adverse events had no significant difference in two groups.Conclusions Octreotide combined with netilmicin sulfate can prevent postoperative infection in suppurative appendicitis,regulate Th17/Treg imbalance,restore immune function,and no significant adverse reactions.
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OBJECTIVE:To establish an ion-pair RP-HPLC method for determination of the concentration of netilmicin sulfate in human serum.METHODS:The determination was performed on Luna C18 column with column temperature set at 40℃;the mobile phase consisted of acetonitrile-water (15∶85,pH 2.0,containing 10 mmol?L-1 sodium heptanesulfonate) at a flow rate of 0.8 mL?min-1.The detection wavelength was set at 205 nm.RESULTS:The linear range of netilmicin was 2～20 mg?L-1(r=0.997 6) with a recovery rate of 93.66%～96.05%.The intra-day and inter-day RSD were both less than 10%,respectively.CONCLUSION:The method is sensitive and simple with accurate and reliable results,and it is able to satisfy the requirement for the determination of serum concentration of netilmicin.
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OBJECTIVE: To determine the content of netilmicin sulfate in serum by a high performance liquid chromatography-indirect photometric determination (HPLC-IPD) method. METHOD: The chromatographic system consisted of Soheisorb C18 column and mobile phase of a solution of methyl alcohol-a buffer of phosphoric acid (pH=2.0) (20∶80), that contained 0.5 mmolL-1 of nicotinamide and 0.3 mmolL-1 of sodium seventhalkyl-sulphonate. The detected wave length was 268 nm. The serum simple of 4 patients was determined. RESULTS: The mean recovery of was 93.41% and detection limits was 50 μgL-1. CONCLUSION: The method is constant, sensitive, and has a good concentration. It is good for determination of netilmicin sulfate concentration in serum.