To reduce the dependency on high-carbon-load chromatographic columns,a new method has been established for the determination of the content of docusate sodium using ion-pair high-performance liquid chromatography(IP-HPLC).Tetrapropylammonium chloride was used as the ion-pair reagent with a mobile phase,composition of acetonitrile:10 mmol/L tetrapropylammonium chloride solution=66∶34,adjusting pH to 6.5 with 0.1%phosphoric acid solution,flow rate of 1.5 mL/min,detection wavelength of 214 nm,column temperature of 35℃,and an injection volume of 25 μL,and quantified by an external standard method.The main peak of docusate sodium exhibited a tailing factor of 1.34.The method showed good linearity within the range of 0.02 mg/mL to 0.40 mg/mL,with a correlation coefficient(r)of 0.999 9.It also demonstrated good repeatability,with recovery ranging from 97.0%to 98.2%(n=6).The quantification limit was 3.31 μg/mL,and the detection limit was 2.76 μg/mL.In summary,the new method shows good durability,a wide linear range,and high sensitivity,it is suitable for the determination of docusate sodium.

To reduce the dependency on high-carbon-load chromatographic columns,a new method has been established for the determination of the content of docusate sodium using ion-pair high-performance liquid chromatography (IP-HPLC). Tetrapropylammonium chloride was used as the ion-pair reagent with a mobile phase, composition of acetonitrile:10 mmol/L tetrapropylammonium chloride solution = 66∶34, adjusting pH to 6.5 with 0.1% phosphoric acid solution,flow rate of 1.5 mL/min, detection wavelength of 214 nm,column temperature of 35 °C, and an injection volume of 25 μL,and quantified by an external standard method. The main peak of docusate sodium exhibited a tailing factor of 1.34. The method showed good linearity within the range of 0.02 mg/mL to 0.40 mg/mL, with a correlation coefficient (r) of 0.999 9. It also demonstrated good repeatability, with recovery ranging from 97.0% to 98.2% (n=6). The quantification limit was 3.31 μg/mL, and the detection limit was 2.76 μg/mL.In summary,the new method shows good durability, a wide linear range, and high sensitivity, it is suitable for the determination of docusate sodium.

Objective To analyze and evaluate the differences between the standards for elemental impurities in pharmaceutical excipients in the"Chinese Pharmacopoeia"and ICH Q3D,and to explore strategies for harmonization between them.Methods This study summarizes and reviews the main differences between the general chapters and specific monographs of pharmaceutical excipients in the 2020 edition of the"Chinese Pharmacopoeia"and its first supplement,compared with ICH Q3D.Results By integrating the harmonization strategies for elemental impurities in foreign pharmacopoeias and the risk assessment results for pharmaceutical excipients,this study proposes harmonization strategies and pathways for the standards of pharmaceutical excipients in the"Chinese Pharmacopoeia."Conclusions A systematic risk assessment of elemental impurities in pharmaceutical excipients in the"Chinese Pharmacopoeia"should be conducted based on their risk levels.The revision methods should be determined and continuously updated according to the assessment results.

Objective To analyze the historical and current inclusion of heavy metals and specific elemental impurity tests in the monographs of pharmaceutical excipients in the Pharmacopeias of the US(USP),Europe(EP)and Japan(JP)pharmacopeias.By examining the characteristics and trends in these pharmacopeias,the study seeks to provide insights that can inform the strategy for incorporating elemental impurity tests in the Chinese Pharmacopoeia and offer guidance for the industry to enhance control over elemental impurities in drugs and excipients.Methods The study reviews the inclusion and revision processes of heavy metals and specific elemental impurity tests in the pharmacopeias of the US,Europe and Japan,focusing on aspects such as the number of excipient monographs,the proportion of heavy metal tests,professional categories,and treatment methods.A comparative analysis with the Chinese Pharmacopoeia was conducted to explore the reasons behind the observed differences and to identify potential future developments.Results The USP contains the largest number of excipient monographs,the EP has the fastest progress in the evaluation of elemental impurities in excipients,the JP relies most heavily on wet chemical methods for testing.Conclusion The strategies of the US,European,and Japanese pharmacopeias can serve as valuable references for the development of elemental impurity testing strategies in the Chinese Pharmacopoeia.It is recommended to classify pharmaceutical excipients by risk level,removing heavy metal tests for low-risk categories and conducting elemental impurity risk assessments for higher-risk mineral-based excipients.The inclusion of specific elemental impurity tests should be determined based on these risk assessments,with specific limits or methods established as needed according to excipient category or individual monographs.

OBJECTIVE: To elucidate the role and underlying mechanism of ubiquitin-specific protease 35 (USP35) in ferroptosis of rheumatoid arthritis-fibroblast like synoviocytes (RA-FLS), thereby enhancing our comprehension of the pathogenesis of RA and identifying potential therapeutic targets for its treatment. METHODS: (1) RA-FLS were cultured in vitro and transduced with lentiviral vectors to establish stable cell lines: A USP35-knockdown line (short hairpin ribonucleic acid of USP35, shUSP35) and its control (negtive control of short hairpin ribonucleic acid, shNC), as well as a overexpression of USP35 line (USP35 OE) and its control (Vector). To investigate the role of USP35 in ferroptosis regulation, a ferroptosis model was induced in RA-FLS by treatment with 1 μmol/L Erastin. The cells were divided into six groups: shNC, shNC + Erastin, shUSP35 + Erastin, Vector, Vector + Erastin, and USP35 OE + Erastin. (2) Cell viability was detected using the cell counting kit-8 (CCK-8). (3) Reactive oxygen species (ROS), malondialdehyde (MDA), glutathione/glutathione disulfide (GSH/GSSG) ratios, and Ferrous ion (Fe²⁺) levels were measured using specific assay kits to evaluate oxidative stress, lipid peroxidation, and glutathione redox status in the cells. (4) Protein expression levels of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) were detected using Western blotting to investigate their potential involvement in USP35-mediated ferroptosis regulation. RESULTS: (1) Compared with the shNC +Erastin group, the cell viability of the shUSP35+Erastin group was significantly decreased (P < 0.001), while it was notably increased in the USP35 OE+Erastin group compared with the Vector+Erastin group (P < 0.001). These findings indicated that USP35 could alleviate the inhibitory effect of Erastin on RA-FLS cell viability. (2) In comparison to the shNC+Erastin group, the levels of ROS (P < 0.001), MDA (P < 0.05), and Fe²⁺ (P < 0.001) were significantly elevated, and the GSH/GSSG ratio was increased (P < 0.05) in the shUSP35+Erastin group. Conversely, the levels of ROS (P < 0.001), MDA (P < 0.05), and Fe²⁺ (P < 0.05) were significantly decreased, and the GSH/GSSG ratio was decreased (P < 0.05) in the USP35 OE+Erastin group compared with the Vector+Erastin group. These results suggested that USP35 could inhibit Erastin-induced oxidative stress and lipid peroxidation in RA-FLS. (3) In Erastin-induced RA-FLS, the expression of USP35 was positively correlated with the protein levels of SLC7A11 and GPX4, indicating a potential mechanism by which USP35 regulated ferroptosis in these cells. CONCLUSION USP35 inhibits ferroptosis in RA-FLS, potentially through the increased expression of SLC7A11 and GPX4.
Ferroptosis ; Humans ; Arthritis, Rheumatoid/metabolism* ; Synoviocytes/pathology* ; Reactive Oxygen Species/metabolism* ; Ubiquitin-Specific Proteases/metabolism* ; Fibroblasts/pathology* ; Cell Survival ; Piperazines/pharmacology* ; Endopeptidases/metabolism* ; Cells, Cultured ; Cell Line ; Amino Acid Transport System y+

Objective:To establish a gas chromatography-mass spectrometry method(GC-MS-MS)for determining the content of methyl p-toluenesulfonate(MTS),ethyl p-toluenesulfonate(ETS),and isopropyl p-toluenesulfonate(IPTS)in tosufloxacin tosylate hydrate.Methods:The HP-1MS(0.250 mm ×30 m,0.50 μm)column was used at progamming temperature,the injection temperature was 250 ℃.The MS conditions were as follow:the ionization mode was EI,the electron voltage was 70 V,the ion source temperature was 250 ℃,the scanning method was MRM,the quantitative ion pairs for MTS,ETS and IPTS were m/z 91 →65,m/z 155→91 and m/z 91→65.Results:The linearity ranges of MTS,ETS and IPTS were 48.779-975.59 ng·mL-1(r=0.998 5),54.586-1 091.7 ng·mL-1(r=0.998 4)and 46.241-924.82 ng·mL-1(r=0.999 8).The average recoveries were 99.47％,99.15％,98.83％(n=9).The MTS,ETS and IPTS were not detected in the 7 batches of tosufloxacin tosylate hydrate.Conclusion:The established method can be used for the determination of MTS,ETS,and IPTS content in tosufloxacin tosylate hydrate.

Objective To provide valuable references and insights for improving the excipient standard system of the Chinese Pharmacopeia and promoting its harmonization with ICH Q3D.By analyzing the harmonization strategies and implementation of excipient standards in the pharmacopoeias of Europe,the United States,and Japan.Methods Through a combination of literature review and case study analysis,this paper introduces the policies and strategies adopted by the pharmacopoeias of three major regions(Europe,the United States,and Japan)in implementing the ICH Q3D guidelines in the field of pharmaceutical excipients.Additionally,it reviews the updates on excipient standards in these regions and analyzes the characteristics of their alignment with ICH Q3D.Results The strategies for implementing ICH Q3D in pharmacopeial excipient standards vary across different regions,with each following distinct approaches and progressing at different rates.Notably,there are significant differences in the establishment of standards for elemental impurities.Conclusion Promoting the harmonization of pharmacopeial excipient standards with ICH Q3D is a challenging and long-term endeavor.It is essential to develop a harmonization strategy that is tailored to China's national context.

Objective:To establish a gas chromatography-mass spectrometry method(GC-MS-MS)for determining the content of methyl p-toluenesulfonate(MTS),ethyl p-toluenesulfonate(ETS),and isopropyl p-toluenesulfonate(IPTS)in tosufloxacin tosylate hydrate.Methods:The HP-1MS(0.250 mm ×30 m,0.50 μm)column was used at progamming temperature,the injection temperature was 250 ℃.The MS conditions were as follow:the ionization mode was EI,the electron voltage was 70 V,the ion source temperature was 250 ℃,the scanning method was MRM,the quantitative ion pairs for MTS,ETS and IPTS were m/z 91 →65,m/z 155→91 and m/z 91→65.Results:The linearity ranges of MTS,ETS and IPTS were 48.779-975.59 ng·mL-1(r=0.998 5),54.586-1 091.7 ng·mL-1(r=0.998 4)and 46.241-924.82 ng·mL-1(r=0.999 8).The average recoveries were 99.47％,99.15％,98.83％(n=9).The MTS,ETS and IPTS were not detected in the 7 batches of tosufloxacin tosylate hydrate.Conclusion:The established method can be used for the determination of MTS,ETS,and IPTS content in tosufloxacin tosylate hydrate.

Objective To provide valuable references and insights for improving the excipient standard system of the Chinese Pharmacopeia and promoting its harmonization with ICH Q3D.By analyzing the harmonization strategies and implementation of excipient standards in the pharmacopoeias of Europe,the United States,and Japan.Methods Through a combination of literature review and case study analysis,this paper introduces the policies and strategies adopted by the pharmacopoeias of three major regions(Europe,the United States,and Japan)in implementing the ICH Q3D guidelines in the field of pharmaceutical excipients.Additionally,it reviews the updates on excipient standards in these regions and analyzes the characteristics of their alignment with ICH Q3D.Results The strategies for implementing ICH Q3D in pharmacopeial excipient standards vary across different regions,with each following distinct approaches and progressing at different rates.Notably,there are significant differences in the establishment of standards for elemental impurities.Conclusion Promoting the harmonization of pharmacopeial excipient standards with ICH Q3D is a challenging and long-term endeavor.It is essential to develop a harmonization strategy that is tailored to China's national context.

Objective To analyze and evaluate the differences between the standards for elemental impurities in pharmaceutical excipients in the"Chinese Pharmacopoeia"and ICH Q3D,and to explore strategies for harmonization between them.Methods This study summarizes and reviews the main differences between the general chapters and specific monographs of pharmaceutical excipients in the 2020 edition of the"Chinese Pharmacopoeia"and its first supplement,compared with ICH Q3D.Results By integrating the harmonization strategies for elemental impurities in foreign pharmacopoeias and the risk assessment results for pharmaceutical excipients,this study proposes harmonization strategies and pathways for the standards of pharmaceutical excipients in the"Chinese Pharmacopoeia."Conclusions A systematic risk assessment of elemental impurities in pharmaceutical excipients in the"Chinese Pharmacopoeia"should be conducted based on their risk levels.The revision methods should be determined and continuously updated according to the assessment results.