To evaluate the application of metagenomic sequencing in identification and tracking of drug-contaminating bacteria.

Both metagenomic sequencing and isolation culturing method were employed to identify and genotype bacteria in two batches of possibly contaminated gel medicines as well as the environmental samples from testing laboratory. Bacteria isolated by culturing method were identified through Gram’s stain，biochemical reaction，MALIDI-TOF-MS，16srDNA sequencing and Bacillus specific PCR. The detected Bacillus cereus were typed by multilocus sequence typing (MLST) .The metagenomic sequencing results were analyzed at the strain level using MetaPhlan software.

Both MLST and MetaPhlan analysis revealed a substantial contamination of Bacillus cereus in gel medicines as well as environmental samples，with the presence of the same Bacillus cereus group. Both metagenomic sequencing and culturing methods detected Paenibacillus，Brevibacillus and Neobacillus in gel medicines，but amplicon sequencing also detected these bacteria in environment which might be the source of contamination.

These findings indicate that metagenomic sequencing technology is reliable and has the advantage over isolation culturing in comprehensively detecting potentially hazardous bacterial species and accurately performing strain-level traceability analysis. It holds significant application value in pharmaceutical contamination identification and traceability.

To establish the first batch of national drug reference standard of L-methionine sulfoxide.

The molecular structure of methionine sulfoxide was confirmed by the methods of IR，NMR and high resolution MS. Moreover，the moisture，residual solvents，residual ignition and related substances of L-methionine sulfoxide were determined，and then，its hygroscopicity，homogeneity and stability were also observed. Finally，mass balance method，HPLC and quantitative NMR were applied to determine and calculate its contents.

The results of experiments showed the structure of L-methionine sulfoxide were confirmed，its contents of moisture，residual ignition，metal elements and related substances were 0.23%，0.20%，10.87 μg·g^-1 and 5.09%. The residual solvents were not detected in the samples. The final content of methionine sulfoxide was 94.5% by mass balance method. The contents of this batch of L-methionine sulfoxide were uniform，and it is stable in short-terms.

The first batch of national drug reference standard of L-methionine sulfoxide was established，and it is used for the inspection for related substances of amino acid drug，which is helpful in normalizing drug quality and guaranteeing drug safety.

To study the whole chain microbial load in the production of a traditional Chinese medicine pill.

A type of traditional Chinese medicine pills prescription was selected as the research object，including the medicinal materials and their purified medicinal materials，intermediates (mixed powder，waiting for inner packaging pills)，and finished products. The microbial limit test method was established according to the 2020 edition of the Chinese Pharmacopoeia（ChP），to detect and analyze the microbial loads of all samples collected throughout the entire chain from medicinal materials to finished products of the traditional Chinese medicine pills.

The microbial content of different medicinal materials varies greatly，and the varieties with higer risk factors for microbial contamination in medicinal materials were Perillae Folium，Pogostemonis Herba，and Angelicae Dahuricae Radix. The production process of Perillae Folium and Pogostemonis Herba needed to be improved and adjusted from “medicinal material to pure medicinal material”. There was a positive correlation between the microbial load of medicinal materials and intermediate and finished products.

The study on the microbial load throughout the entire production chain of traditional Chinese patent medicines can help us to understand the transmission of microorganisms at each stage. This knowledge is crucial for identifying weak links in the production process and the key areas for process control, and has an important guiding significance for traditional Chinese patent medicines manufacturers to improve and explore their production process.

To establish an integrated model of biosensing technology for the study of zebrafish，and to study and verify the interaction between cetirizine hydrochloride，fexofenadine hydrochloride，mizolastine，and ebastine，with the key target of allergic rhinitis，macrophage migration inhibitory factor（MIF）.

A MIF-high electron mobility transistor(HEMT) biosensor was constructed using AlGaAs/GaAs HEMT as the sensing element and MIF as the biological element. The interaction strength between cetirizine hydrochloride，fexofenadine hydrochloride，mizolastine，and ebastine and MIF was characterized. Furthermore，a zebrafish immune inflammation model was established. The number of neutrophil migration in the blank control group，model group，positive drug group，and low，medium，and high-dose drug groups were recorded. And the drug inflammation inhibition rate were calculated.

Cetirizine hydrochloride exhibited the strongest binding ability to MIF，with a dissociation constant of 7.05×10^-13 mol·L^-1. The K_D for the interactions between fexofenadine hydrochloride，mizolastine，and ebastine with MIF were 2.34×10^-8 mol·L^-1，1.94×10^-7 mol·L^-1 and 2.44×10^-8 mol·L^-1，respectively. All of them had binding effects with MIF. Further the validation using the zebrafish immune anti-inflammatory model revealed that all four antihistamines significantly reduced the number of neutrophil migrations，among which 100 μmol·L^-1 of cetirizine hydrochloride achieved a neutrophil migration inhibition rate of 68.5%.

This study explores the interaction between antihistamines and the key protein target of AR through the integration of biosensing technology and zebrafish experiments. It was found that MIF is a potential target for antihistamine drugs to exert their pharmacological effects. It provides an important reference for research on drug efficacy and its association with targets.

To systematically characterize and simultaneous determine 13 chemical components (neochlorogenic acid，chlorogenic acid，cryptochlorogenic acid，luteolin-7-glucuronide，cynaroside，isochlorogenic acid B，isochlorogenic acid A，apigenin-7-glucuronide，isochlorogenic acid C，deoxyelephantopin，isodeoxyelephantopin，isoscabertopin and scabertopin) in Elephantopi Herba based on ultra performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q TOF MS/MS).

UPLC-Q TOF MS/MS technology combined with sequential window acquisition of all theoretical mass spectra (SWATH) mode was used to collect data of different batches of Elephantopi Herba samples. The separation was performed on a Waters HSS T3 C₁₈(100 mm×2.1 mm，1.8 μm) column with mobile phase consisting of acetonitrile and 0.1% formic acid water solution. The flow rate of gradient elution was 0.4 mL·min^-1，the column temperature was 35 ℃ and the injection volume was 2 μL. The electrospray ionization (ESI) source was employed to collect data under both positive and negative ion modes. With reference to reference substances and relevant literatures，chemical components in Elephantopi Herba were identified. At the same time，the determination method for 13 chemical components in Elephantopi Herba was established and validated.

In this study，the cleavage patterns of different classes of compounds were summarized，and 36 chemical components were initially identified，including 20 organic acids，7 flavonoids，6 sesquiterpene lactones，1 coumarin and 2 other components. All of the analytes showed good linearity (r≥0.999 0) in the tested ranges. The precision，repeatability and stability of the method were good for the 13 components. The average recoveries were in the range of 94.9%-103.5% with relative standard deviations (RSDs) ≤3.8%. The chemical compositions of different batches of Elephantopi Herba were basically similar，but there were certain differences in the contents of 13 components.

In this study，comprehensive characterization of the chemical constituents and relative quantitative analysis of Elephantopi Herba are carried out，and a rapid and efficient qualitative analysis method of Elephantopi Herba is established by UPLC-Q TOF MS/MS，which provides a reference for the screening and rational exploitation of the medicinal substances of Elephantopi Herba，and methodological reference and data support for the quality control and development of Elephantopi Herba.

To classify the microbiological examination methods of live microecological products according to the results of suitability test for the enumeration method，and establish the decision-making method for microbiological examination of live microecological products.

The suitability test of the microbiological examination method of live microecological products was performed according to the requirements of the General Chapter 1105 in the Chinese Pharmacopoeia Vol Ⅳ. Escherichia coli，Staphylococcus aureus，Bacillus subtilis，Pseudomonas aeruginosa，Candida albicans and Aspergillus niger were used as the test strains. Tryptic Soy Agar，Sabouraud Dextrose Agar，Rose Bengal Agar and Rose Bengal Agar Ⅱ were used as medium.

For live microecological products composed of anaerobic bacteria or microorganisms with growth characteristics significantly different from the test strains，the suitability test for the method could be performed according to General Chapter 1105. For live microecological products containing Bacillus and enterococcus，the suitability test for the fungal enumeration method could be performed according to General Chapter 1105. Live microecological products could not be tested for suitability of the method due to the influence of the component microorganisms，gram-negative bacteria could be controlled using selective medium. In addition，some potentially harmful microorganisms could be controlled based on risk assessment according to the route of administration and the population of drug users.

This study provides a basis for the selection of the microbiological examination methods for live microecological products，and further complements and improves the quality standard system of live microecological products.

To develop a novel and efficient assay for the determination of free formaldehyde content in vaccines，and to compare the results with the method of the Chinese Pharmacopoeia(ChP) 2020 edition.

Vaccine samples were added directly into headspace vials without any pretreatment and tested after mixed with a new derivatization reagent，1% p-toluenesulfonic acid-ethanol solution (1% TsOH-EtOH solution). The concentration of the reagent，the dosage and the optimal derivatization conditions (headspace incubation temperature and time) were tested and confirmed. A DB-624 gas capillary column was used with temperature programming. The detector was a hydrogen-ion flame detector (FID) and the sample was injected in headspace.

The linear range was 0.25-100 μg·mL^-1（r=0.999 5），the detection limit and the quantification limit were 0.10 μg·mL^-1 and 0.25 μg·mL^-1，respectively. The recovery rates of several kinds of vaccines were all over 94%，and the RSDs were all less than 6%，which were in line with the requirements of specificity，precision and durability. There were no significant differences between the results of multiple batches and those determined by ChP 2020 methods.

In this paper，a novel derivatization reagent (1% TsOH-EtOH solution) was developed and validated for the determination of free formaldehyde content in vaccines，which is simple，efficient and can achieve high-throughput detection. The method can just solve the problems in other current detection methods. The method of derivatization headspace gas chromatography for the determination of free formaldehyde content is applicable to vaccines and other biologics，and provide a reference for chemicals，traditional Chinese medicine and excipients.

To establish an HPLC method for the simultaneous determination of eight components including salvianic acid A sodium，geniposidic acid，phellodendrine，salvianolic acid B，palmatine，berberine，atractylodin，tanshinone Ⅱ_A in Shuangshi Tonglin capsules.

The determination was performed on a Capcell Pak MG Ⅱ C₁₈ column (250 mm×4.6 mm，5 μm) with the mobile phase consisting of acetonitrile-water(containing 0.1% phosphoric acid)-water(containing 0.1% phosphoric acid and 0.2% triethylamine，pH 6.0) in a gradient mode at a flow rate of 1.0 mL·min^-1. The column temperature was set at 30 ℃，the injection volume was 10 μL，and the detection wavelength was 280 nm (0-13.4 min）for salvianic acid A sodium，238 nm (13.5-17.0 min) for geniposidic acid，280 nm （17.1-51.0 min）for phellodendrine，salvianolic acid B，345 nm（51.1.1-70.0 min）for palmatine，berberine，336 nm（70.1-78.0 min）for atractylodin and 268 nm(78.1-90.0 min)for tanshinone Ⅱ_A.

Salvianic acid A sodium，geniposidic acid，phellodendrine，salvianolic acid B，palmatine，berberine，atractylodin，tanshinoneⅡ_A had good linearities in their respective linear ranges with all linear correlation coefficients ≥ 0.999 5 and RSDs of the precision，repeatability and stability less than 2.0%. The average recoveries were 101.3%，98.2%，97.3%，98.1%，96.6%，97.9%，98.7%，99.6%，with RSDs lower than 2.0%. The contents of the above eight components in three batches of samples was 4.47-5.51 mg·g^-1，0.93-1.44 mg·g^-1，1.00-1.07 mg·g^-1，5.72-8.67 mg·g^-1，0.64-0.69 mg·g^-1，1.62-1.90 mg·g^-1，0.055-0.088 mg·g^-1，0.29-0.44 mg·g^-1，respectively.

The proposed method is rapid，sensitive and specific，which can be used for determination the contents of eitht components in Shuangshi Tonglin capsules.

To establish an HPLC method for determination of the impurity profile in furosemide and its injection. At the same time，applying this method to detect and analyze products from many domestic and foreign enterprises，to evaluate the status quo of impurity control in API and injection，and the correlation of major degraded impurities in injection with prescription and packaging materials.

A YMC Hydrosphere C₁₈ column（250 mm×4.6 mm，3 μm）was used，and the mobile phase was 0.05% TFA solution (pH 2.23)-methanol-acetonitrile at the flow rate of 1.0 mL·min^-1，gradient elution. Detection wavelength was set at 238 nm and 277 nm and column temperature was 30 ℃. Impurity reference was used for localization and the relative retention time of each impurity was calculated. The known impurities were calculated using the principal component self-control method with correction factor，the unknown impurities were determined by principal component without correction factor.

The method for the determination of 11 kinds of known impurities，the potential genotoxic impurity in furosemide，its injection was established，the separation degree of all impurities met the requirements，and the sources of the impurities were identified by forced degradation test. The detected quantity of degraded impurity C and degraded impurity G in the injections produced by 2 to 3 companies exceeded the identification limit in ICH by 0.2%，the amount of potential genotoxic impurity furfural detected in the injection of 5 enterprises was much higher than that of the reference preparation，other impurities were the same as the reference preparation.

The established HPLC method can be used for rapid detection and analysis of impurities in furosemide and its injection. The impurity control level of injection produced by only 2 domestic enterprises is basically consistent with the reference preparation，others need to optimize prescription and packaging materials. This study can provide reference for improving the safety of furosemide injection and evaluating the quality consistency of generic drugs.