In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics.Similarities and variations of components present significant analytical challenges.A two-dimensional(2D)liquid chromatography-mass spectrometry(LC-MS)method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium(CMS).A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated.For efficient and high-accuracy screening of CMS,a targeted method based on a self-constructed high resolution(HR)mass spectrum database of CMS components was established.The database was built based on the commercial MassHunter Personal Compound Database and Library(PCDL)software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening.On this basis,the unknown peaks in the CMS chromatograms were deduced and assigned.The molecular formula,group composition,and origins of a total of 99 compounds,of which the combined area percentage accounted for more than 95％of CMS components,were deduced by this 2D-LC-MS method combined with the MassHunter PCDL.This profiling method was highly efficient and could distinguish hundreds of components within 3 h,providing reliable results for quality control of this kind of complex drugs.

In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics. Similarities and variations of components present significant analytical challenges. A two-dimensional (2D) liquid chromatography-mass spectrometr (LC-MS) method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium (CMS). A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated. For efficient and high-accuracy screening of CMS, a targeted method based on a self-constructed high resolution (HR) mass spectrum database of CMS components was established. The database was built based on the commercial MassHunter Personal Compound Database and Library (PCDL) software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening. On this basis, the unknown peaks in the CMS chromatograms were deduced and assigned. The molecular formula, group composition, and origins of a total of 99 compounds, of which the combined area percentage accounted for more than 95% of CMS components, were deduced by this 2D-LC-MS method combined with the MassHunter PCDL. This profiling method was highly efficient and could distinguish hundreds of components within 3 h, providing reliable results for quality control of this kind of complex drugs.

Objective To determine the related substances in ornidazole active pharmaceutical ingredient(API)and injections using high performance liquid chromatography(HPLC)and to study the impurity profile of ornidazole using liquid chromatography-tandem mass spectrometry(LC-MS/MS)combined with forced degradation tests,aiming to clarify the sources of impurities and their correlation with the prescription and production process and providing technical support for the unified evaluation and quality control of this product.Methods A Phenomenex Luna C18column(4.6 mm×250 mm,5 μm)was used for the separation of ornidazole and its impurities,with 0.000 5%formic acid as mobile phase A and methanol as mobile phase B under gradient elution.The impurity content of 4 batches of APIs,3 batches of reference preparations,and 11 batches of domestic generic preparations were determined.The structure of unknown impurities was predicted using Jet Stream Ion Focusing Electrospray Ionization-Time of Flight Mass Spectrometry(AJS-TOF-MS/MS),and the sources of impurities were identified combined with forced degradation experiments,the prescription and the production process of various manufacturers.Results Ornidazole and its known impurities were well separated under the chromatographic conditions.The structures of five unknown impurities were inferred,and the sources of the impurities were identified.Conclusion This study provides a reference for impurity analysis,quality control,and overall evaluation of ornidazole API and injection.

Objective To determine the related substances in ornidazole active pharmaceutical ingredient(API)and injections using high performance liquid chromatography(HPLC)and to study the impurity profile of ornidazole using liquid chromatography-tandem mass spectrometry(LC-MS/MS)combined with forced degradation tests,aiming to clarify the sources of impurities and their correlation with the prescription and production process and providing technical support for the unified evaluation and quality control of this product.Methods A Phenomenex Luna C18column(4.6 mm×250 mm,5 μm)was used for the separation of ornidazole and its impurities,with 0.000 5%formic acid as mobile phase A and methanol as mobile phase B under gradient elution.The impurity content of 4 batches of APIs,3 batches of reference preparations,and 11 batches of domestic generic preparations were determined.The structure of unknown impurities was predicted using Jet Stream Ion Focusing Electrospray Ionization-Time of Flight Mass Spectrometry(AJS-TOF-MS/MS),and the sources of impurities were identified combined with forced degradation experiments,the prescription and the production process of various manufacturers.Results Ornidazole and its known impurities were well separated under the chromatographic conditions.The structures of five unknown impurities were inferred,and the sources of the impurities were identified.Conclusion This study provides a reference for impurity analysis,quality control,and overall evaluation of ornidazole API and injection.

The UPLC fingerprint of colistimethate sodium was established for the study of quality consistency.The chromatographic column was Acquity UPLC? Peptide CSH C18 (2.1 mm × 150 mm, 1.7 μm).The mobile phase A was phosphate buffer-acetonitrile (19∶1), and the mobile phase B was phosphate buffer-acetonitrile (1∶1).The mobile phase was in gradient elution at a flow rate of 0.3 mL/min.The column temperature was set at 30 °C and the detection wavelength was 210 nm.The similarity of the fingerprints was analyzed with the Similarity Evaluation System for Chromatographic Fingerprint of Tradition Chinese Medicine (Version 2012) in combination with content determination of multiple index components to evaluate the quality consistency of imported and domestic bulk drugs.The result showed that both the original and generic bulk drugs met the specified limit requirements in the European Pharmacopoeia standards, and that their UPLC fingerprints were highly similar, indicating that the quality of the two substances was consistent.Establishing a fingerprint for similarity evaluation and combining it with the results of indicator component content determination as a comprehensive evaluation method for the study of drug quality consistency of complex components has the characteristics of fast, accurate, and comprehensive, which is helpful for drug quality evaluation and provides ideas for the evaluation of antibiotic quality consistency of complex components.

OBJECTIVES: This population-based, prospective cohort study investigated the association between glaucoma and mortality in older adults. METHODS: Participants aged 45 years or older at baseline (47.9% male) were enrolled in 2011 for the China Health and Retirement Longitudinal Study (CHARLS). All-cause mortality was observed during 7 years of follow-up. The baseline data were collected in the 2011 CHARLS, and participants were followed up for 7 years (until 2018). The risk of all-cause mortality was investigated using Cox proportional-hazards regression with age as the time scale, adjusting for significant risk factors and comorbid conditions. RESULTS: Among the 14,803 participants included, the risk of all-cause death was significantly higher among people with glaucoma than among those without glaucoma, after adjustment for other confounders (hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.04 to 2.03). In a subgroup analysis based on the mean age of death, among those who were 75 years and older (n=1,231), the risk of all-cause death was significantly higher in patients with glaucoma than in those without glaucoma (HR, 1.89; 95% CI, 1.24 to 1.89). CONCLUSIONS Participants with glaucoma had a higher risk of all-cause mortality, especially those aged 75 years and above. Our findings revealed potential mechanisms underlying an association between glaucoma and all-cause mortality. They also highlighted the importance of glaucoma management to prevent premature death in middle-aged and older adults.

OBJECTIVES: This study evaluated the association between obesity and glaucoma in middle-aged and older people. A population-based retrospective cohort study was conducted using data from the China Health and Retirement Longitudinal Study. METHODS: Glaucoma was assessed via self-reports. Multivariate logistic regression analysis and a Cox proportional hazards model were used to assess the relationship between obesity and glaucoma risk. RESULTS: Older males living in urban areas who were single, smokers, and non-drinkers were found to have a significantly higher incidence of glaucoma (all p<0.05). Diabetes, hypertension, and kidney disease were also associated with higher glaucoma risk, while dyslipidemia was associated with lower risk (all p<0.05). After the model was adjusted for demographic, socioeconomic, and health-related variables, obesity was significantly associated with a 10.2% decrease in glaucoma risk according to the Cox proportional hazards model (hazard ratio, 0.90; 95% confidence interval [CI], 0.83 to 0.97) and an 11.8% risk reduction in the multivariate logistic regression analysis (odds ratio, 0.88; 95% CI, 0.80 to 0.97). A further subgroup analysis showed that obesity was associated with a reduced risk of glaucoma in people living in rural areas, in smokers, and in those with kidney disease (all p<0.05). Obesity also reduced glaucoma risk in people with diabetes, hypertension, or dyslipidemia more than in healthy controls (all p<0.05). CONCLUSIONS This cohort study suggests that obesity was associated with a reduced risk of glaucoma, especially in rural residents, smokers, and people with kidney disease. Obesity exerted a stronger protective effect in people with diabetes, hypertension, or dyslipidemia than in healthy people.

A novel method was developed for the content assay and related substances determination of neomycin sulfate by high performance liquid chromatography combined with pulsed amperometric detection(HPLC-PAD). The HPLC was performed on Thermo AcclaimTMAmG C18(4. 6 mm×150 mm, 3 μm). The mobile phase consisted of aqueous solution with 2% trifluoroacetic acid containing 0. 01% pentafluoropropionic acid and 0. 6%NaOH. The pulsed amperometric detector was operated with aquadruple-potential waveform for the detection. Neomycin B, Neomycin C and thirteen related substances were adequately separated by the established HPLC conditions. The limits of detection(LOD)and quantification(LOQ)of neomycin B and neomycin C were both 1. 75 ng and 3. 5 ng, respectively. Good linearities of neomycin B and neomycin C were found in their respective ranges which their correlation coefficients were greater than 0. 998 5. The established method is characterized by high specificity, sensitivity and wide range of linearity which has a good application prospect and provides the basis for improving the standard and quality control of neomycin sulfate.

Objective To explore the verification methods for the performance of quantitative detection kit of anti-dsDNA antibodiy with enzyme-linked immunosorbent assay (ELISA).Methods The precision was verified according to the EP15-A2 document approved by the American Clinical and Laboratory Standards Institute(CLSI).The accuracy was verified by detecting the samples of previous external quality evaluation(EQA),compared with the comparative kits and recovery test.The lower limit of detection(LLD) was calculated by the results of blank samples.The cut-off value was verified according to the C28-A3C document approved by CLSI and CNAS-CL39:Guidance on the Application of Accreditation Criteria for the Medical Laboratory Quality and Competence in the Field of Clinical Qualitative Immunology respectively.The improved Doumas method was used to verify the range of linearity.Results The measured intra-assay and inter-assay coefficients of variation were lower than those announced by the manufacturer or the calculated values according to the EP15-A2 document.The coincidence rates for negative and positive EQA samples between detected and expected values were 98.4％ (63/64) and 100％ (20/20) respectively.The total coincidence rate was 98.8％ (83/84).The coincidence rate for negative and positive samples between the results from candidate and comparative kits were 91.2％ (52/57) and 87.0％ (40/46) respectively.The total coincidence rate was 89.3％ (92/103) and the Kappa value was 0.783 (P =0.062),which implied excellent consistency between the two kits.The mean recovery rate was 99.65％.The measured LLD was 0.5 IU/mL which was lower than 1 IU/mL as claimed by the manufacturer.The measured cut-off value according to the CNAS-CL39 document was 18.51 IU/mL,which was close to 20 IU/mL announced by the manufacturer.Based on the C28-A3C method,the cut-off value could be approved.The linear regression equation was Y =0.978 8X-3.125 4,r2 =0.996 1.There was no statistical difference between the intercept (-3.125 4) and 0 (t =-0.772,P =0.483).The range of linearity was from 1.6 to 212.5 IU/mL,which was consistent with the values declared by the manufacturer.All the verifications of the five performances above-mentioned could be passed.Conclusion The precision,accuracy,LLD,cut-off value and range of linearity of the candidate quantitative ELISA kit for anti-dsDNA antibody were consistent with the statement of the manufacturer,which indicated the performance of the kits may meet the requirements of clinic diagnosis and treatment.A series of methods used in this study provided a simple protocol for verifying the performance of quantitative ELISA kits.

Background The aqueous flare is obvious in uveitic glaucomatous eye due to the damage of blood-aqueous barrier,especially following intraocular surgery.How to quantitatively determine the aqueous flare is important for us to understand the severity of inflammatory response.Objective This study was to assess inflammatory response following Ahmed glaucoma valve implantation in uveitic glaucomatous eye.Methods A nonrandomized controlled study was carried out under the approval of Ethic Committee of Zhongshan Ophthalmic Center of Sun Yat-sen University.Twenty-nine eyes of 29 subjects with refractory glaucoma were enrolled this hospital from October 2011 through July 2012.The patients were divided into the uveitic glaucoma group (10 eyes) and the other refractory glaucoma group (19 eyes) with the matched demography,and Ahmed glaucoma valve implantation was performed on all the eyes under the informed consent of each patient.The aqueous flare value was determined with FC-2000 flare-cell photometry and intraocular pressure (IOP) was measured with Goldmann tonometer before surgery and 1 day,3 days,1 week,2 weeks,1 month and 3 months after surgery.The outcomes were compared between the two groups,and the correlation of aqueous flare value with IOP was analyzed.Results In the uveitic glaucoma group,the aqueous flare values were 21.10 (10.50,38.58) photoparticles/ms,88.00 (23.55,168.63) photoparticles/ms and 29.90 (8.90,65.18)photoparticles/ms 1 day,3 days and 1 week after surgery,which were significantly higher than 13.53 (7.60,24.00) photoparticles/ms before surgery (all at P＜0.01).The same trend was found in the other refractory glaucoma group.In addition,the aqueous flare value was higher in the uveitic glaucoma group than that in the other refractory glaucoma group in 3 months after surgery (q=-3.445,P＜0.01).No significant differences were seen in IOP between the two groups at various time points (all at P＞0.05).Also,no significant correlations were seen between IOP and aqueous flare value in all patients at various time points (preoperation:rs =0.136,P =0.481; postoperative 1 day:rs =0.019,P =0.922 ; postoperative 3 days:rs =-0.035,P =0.858 ; postoperative 1 week:rs =0.317,P=0.094; postoperative 2 weeks:rs =0.034,P =0.861 ; postoperative 1 month:rs =-0.094,P =0.628 ; postoperative 3 months:rs =0.065,P =0.738).Conclusions FC-2000 flare-cell photometry can reflect the inflammatory reaction of the anterior chamber following Ahmed glaucoma valve implantation in various types of refractory glaucomatous eyes.The postoperative inflammatory response is more serious and lasting in uveitic glaucomatous eye.