1.Modified Ditan Tang Regulates Biorhythm-related Genes in Rat Model of Non-alcoholic Fatty Liver Disease
Zhiwen PANG ; Yu LIU ; Nan SONG ; Jie WANG ; Jingxuan ZHU ; Zhen HUA ; Yupeng PEI ; Qun WANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(6):115-124
ObjectiveTo investigate the effects of modified Ditan tang on genes related to the transcription-translation feedback loop (TTFL) of biorhythm in the rat model of non-alcoholic fatty liver disease (NAFLD) and its mechanism for prevention and treatment of NAFLD. MethodsSixty-five healthy SPF male SD rats were randomly assigned into blank (n=20), model (n=15), and low-, medium-, and high-dose (2.68, 5.36, and 10.72 g·kg-1·d-1, respectively) modified Ditan tang (n=10) groups. Other groups except the blank group were fed a high-fat diet for 12 weeks. The modified Ditan tang groups were treated with the decoction at corresponding doses by gavage, and the blank and model groups were treated with an equal volume of normal saline from the 9th week for 4 weeks. The levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in the serum were measured by an automatic biochemical analyzer. TG and non-esterified fatty acid (NEFA) assay kits were used to measure the levels of TG and NEFA in the liver. The pathological changes in the hypothalamus and liver were observed by hematoxylin-eosin staining, and the lipid deposition in the liver was observed by oil red O staining. The levels of brain-muscle ARNT-like protein 1 (BMAL1/ARNTL) in the hypothalamus and liver were determined by immunohistochemical staining. The mRNA and protein levels of BMAL1, circadian locomotor output cycles kaput (CLOCK), period circadian clock 2 (PER2), and cryptochrome1 (Cry1) in the hypothalamus and liver were determined by Real-time PCR and Western blot, respectively. ResultsCompared with the blank group, the model group showed elevated levels of TG, TC, LDL-C, AST, and ALT (P<0.01) and a lowered level of HDL-C (P<0.05) in the serum, elevated levels of TG and NEFA in the liver (P<0.01), pyknosis and deep staining of hypothalamic neuron cells, and a large number of vacuoles in the brain area. In addition, the model group showed lipid deposition in the liver, up-regulated mRNA and protein levels of CLOCK and BMAL1 (P<0.01), and down-regulated mRNA and protein levels of Cry1 and PER2 (P<0.01) in the hypothalamus and liver. Compared with the model group, all the three modified Ditan tang groups showed lowered levels of TG, TC, LDL-C, ALT, and AST (P<0.05, P<0.01) and an elevated level of HDL-C (P<0.05) in the serum, and lowered levels of TG and NEFA (P<0.05, P<0.01) in the liver. Furthermore, the three groups showed alleviated pyknosis and deep staining of hypothalamic neuron cells, reduced lipid deposition in the liver, down-regulated mRNA and protein levels of CLOCK and BMAL1 (P<0.05, P<0.01), and up-regulated mRNA and protein levels of Cry1 and PER2 (P<0.05, P<0.01) in the hypothalamus and liver. ConclusionModified Ditan tang can reduce lipid deposition in the liver and regulate the expression of CLOCK, BMAL1, Cry1, and PER2 in the TTFL of NAFLD rats.
2.Mitochondial-located miRNAs in The Regulation of mtDNA Expression
Peng-Xiao WANG ; Le-Rong CHEN ; Zhen WANG ; Jian-Gang LONG ; Yun-Hua PENG
Progress in Biochemistry and Biophysics 2025;52(7):1649-1660
Mitochondria, functioning not only as the central hub of cellular energy metabolism but also as semi-autonomous organelles, orchestrate cellular fate decisions through their endogenous mitochondrial DNA (mtDNA), which encodes core components of the electron transport chain. Emerging research has identified microRNAs localized within mitochondria, termed mitochondria-located microRNAs (mitomiRs). Recent studies have revealed that mitomiRs are transcribed from nuclear DNA (nDNA), processed and matured in the cytoplasm, and subsequently transported into mitochondria. mitomiRs regulate mtDNA through diverse mechanisms, including modulation of mtDNA expression at the translational level and direct binding to mtDNA to influence transcription. Aberrant expression of mitomiRs leads to mitochondrial dysfunction and contributes to the pathogenesis of metabolic diseases. Restoring mitomiR expression to physiological levels using mitomiRs mimics or inhibitors has been shown to improve mitochondrial function and alleviate related diseases. Consequently, the regulatory mechanisms of mitomiRs have become a major focus in mitochondrial research. Given that mitomiRs are located in mitochondria, targeted delivery strategies designed for mtDNA can be adapted for the delivery of mitomiRs mimics or inhibitors. However, numerous intracellular and extracellular barriers remain, highlighting the need for more precise and efficient delivery systems in the future. The regulation of mtDNA expression mediated by mitomiRs not only expands our understanding of miRNA functions in post-transcriptional gene regulation but also provides promising molecular targets for the treatment of mitochondrial-related diseases. This review systematically summarizes recent research progress on mitomiRs in regulating mtDNA expression and discusses the underlying mechanisms of mitomiRs-mtDNA interactions. Additionally, it provides new perspectives on precision therapeutic strategies, with a particular emphasis on mitomiRs-based regulation of mitochondrial function in mitochondrial-related diseases.
3.The Near-infrared II Emission of Gold Clusters and Their Applications in Biomedicine
Zhen-Hua LI ; Hui-Zhen MA ; Hao WANG ; Chang-Long LIU ; Xiao-Dong ZHANG
Progress in Biochemistry and Biophysics 2025;52(8):2068-2086
Optical imaging is highly valued for its superior temporal and spatial resolution. This is particularly important in near-infrared II (NIR-II, 1 000-3 000 nm) imaging, which offers advantages such as reduced tissue absorption, minimal scattering, and low autofluorescence. These characteristics make NIR-II imaging especially suitable for deep tissue visualization, where high contrast and minimal background interference are critical for accurate diagnosis and monitoring. Currently, inorganic fluorescent probes—such as carbon nanotubes, rare earth nanoparticles, and quantum dots—offer high brightness and stability. However, they are hindered by ambiguous structures, larger sizes, and potential accumulation toxicity in vivo. In contrast, organic fluorescent probes, including small molecules and polymers, demonstrate higher biocompatibility but are limited by shorter emission wavelengths, lower quantum yields, and reduced stability. Recently, gold clusters have emerged as a promising class of nanomaterials with potential applications in biocatalysis, fluorescence sensing, biological imaging, and more. Water-soluble gold clusters are particularly attractive as fluorescent probes due to their remarkable optical properties, including strong photoluminescence, large Stokes shifts, and excellent photostability. Furthermore, their outstanding biocompatibility—attributed to good aqueous stability, ultra-small hydrodynamic size, and high renal clearance efficiency—makes them especially suitable for biomedical applications. Gold clusters hold significant potential for NIR-II fluorescence imaging. Atomic-precision gold clusters, typically composed of tens to hundreds of gold atoms and measuring only a few nanometers in diameter, possess well-defined three-dimensional structures and clear spatial coordination. This atomic-level precision enables fine-tuned structural regulation, further enhancing their fluorescence properties. Variations in cluster size, surface ligands, and alloying elements can result in distinct physicochemical characteristics. The incorporation of different atoms can modulate the atomic and electronic structures of gold clusters, while diverse ligands can influence surface polarity and steric hindrance. As such, strategies like alloying and ligand engineering are effective in enhancing both fluorescence and catalytic performance, thereby meeting a broader range of clinical needs. In recent years, gold clusters have attracted growing attention in the biomedical field. Their application in NIR-II imaging has led to significant progress in vascular, organ, and tumor imaging. The resulting high-resolution, high signal-to-noise imaging provides powerful tools for clinical diagnostics. Moreover, biologically active gold clusters can aid in drug delivery and disease diagnosis and treatment, offering new opportunities for clinical therapeutics. Despite the notable achievements in fundamental research and clinical translation, further studies are required to address challenges related to the standardized synthesis and complex metabolic behavior of gold clusters. Resolving these issues will help accelerate their clinical adoption and broaden their biomedical applications.
4.Analysis of T7 RNA Polymerase: From Structure-function Relationship to dsRNA Challenge and Biotechnological Applications
Wei-Chen NING ; Yu HUA ; Hui-Ling YOU ; Qiu-Shi LI ; Yao WU ; Yun-Long LIU ; Zhen-Xin HU
Progress in Biochemistry and Biophysics 2025;52(9):2280-2294
T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.
5.Targeting PPARα for The Treatment of Cardiovascular Diseases
Tong-Tong ZHANG ; Hao-Zhuo ZHANG ; Li HE ; Jia-Wei LIU ; Jia-Zhen WU ; Wen-Hua SU ; Ju-Hua DAN
Progress in Biochemistry and Biophysics 2025;52(9):2295-2313
Cardiovascular disease (CVD) remains one of the leading causes of mortality among adults globally, with continuously rising morbidity and mortality rates. Metabolic disorders are closely linked to various cardiovascular diseases and play a critical role in their pathogenesis and progression, involving multifaceted mechanisms such as altered substrate utilization, mitochondrial structural and functional dysfunction, and impaired ATP synthesis and transport. In recent years, the potential role of peroxisome proliferator-activated receptors (PPARs) in cardiovascular diseases has garnered significant attention, particularly peroxisome proliferator-activated receptor alpha (PPARα), which is recognized as a highly promising therapeutic target for CVD. PPARα regulates cardiovascular physiological and pathological processes through fatty acid metabolism. As a ligand-activated receptor within the nuclear hormone receptor family, PPARα is highly expressed in multiple organs, including skeletal muscle, liver, intestine, kidney, and heart, where it governs the metabolism of diverse substrates. Functioning as a key transcription factor in maintaining metabolic homeostasis and catalyzing or regulating biochemical reactions, PPARα exerts its cardioprotective effects through multiple pathways: modulating lipid metabolism, participating in cardiac energy metabolism, enhancing insulin sensitivity, suppressing inflammatory responses, improving vascular endothelial function, and inhibiting smooth muscle cell proliferation and migration. These mechanisms collectively reduce the risk of cardiovascular disease development. Thus, PPARα plays a pivotal role in various pathological processes via mechanisms such as lipid metabolism regulation, anti-inflammatory actions, and anti-apoptotic effects. PPARα is activated by binding to natural or synthetic lipophilic ligands, including endogenous fatty acids and their derivatives (e.g., linoleic acid, oleic acid, and arachidonic acid) as well as synthetic peroxisome proliferators. Upon ligand binding, PPARα activates the nuclear receptor retinoid X receptor (RXR), forming a PPARα-RXR heterodimer. This heterodimer, in conjunction with coactivators, undergoes further activation and subsequently binds to peroxisome proliferator response elements (PPREs), thereby regulating the transcription of target genes critical for lipid and glucose homeostasis. Key genes include fatty acid translocase (FAT/CD36), diacylglycerol acyltransferase (DGAT), carnitine palmitoyltransferase I (CPT1), and glucose transporter (GLUT), which are primarily involved in fatty acid uptake, storage, oxidation, and glucose utilization processes. Advancing research on PPARα as a therapeutic target for cardiovascular diseases has underscored its growing clinical significance. Currently, PPARα activators/agonists, such as fibrates (e.g., fenofibrate and bezafibrate) and thiazolidinediones, have been extensively studied in clinical trials for CVD prevention. Traditional PPARα agonists, including fenofibrate and bezafibrate, are widely used in clinical practice to treat hypertriglyceridemia and low high-density lipoprotein cholesterol (HDL-C) levels. These fibrates enhance fatty acid metabolism in the liver and skeletal muscle by activating PPARα, and their cardioprotective effects have been validated in numerous clinical studies. Recent research highlights that fibrates improve insulin resistance, regulate lipid metabolism, correct energy metabolism imbalances, and inhibit the proliferation and migration of vascular smooth muscle and endothelial cells, thereby ameliorating pathological remodeling of the cardiovascular system and reducing blood pressure. Given the substantial attention to PPARα-targeted interventions in both basic research and clinical applications, activating PPARα may serve as a key therapeutic strategy for managing cardiovascular conditions such as myocardial hypertrophy, atherosclerosis, ischemic cardiomyopathy, myocardial infarction, diabetic cardiomyopathy, and heart failure. This review comprehensively examines the regulatory roles of PPARα in cardiovascular diseases and evaluates its clinical application value, aiming to provide a theoretical foundation for further development and utilization of PPARα-related therapies in CVD treatment.
6.Adolescent Smoking Addiction Diagnosis Based on TI-GNN
Xu-Wen WANG ; Da-Hua YU ; Ting XUE ; Xiao-Jiao LI ; Zhen-Zhen MAI ; Fang DONG ; Yu-Xin MA ; Juan WANG ; Kai YUAN
Progress in Biochemistry and Biophysics 2025;52(9):2393-2405
ObjectiveTobacco-related diseases remain one of the leading preventable public health challenges worldwide and are among the primary causes of premature death. In recent years, accumulating evidence has supported the classification of nicotine addiction as a chronic brain disease, profoundly affecting both brain structure and function. Despite the urgency, effective diagnostic methods for smoking addiction remain lacking, posing significant challenges for early intervention and treatment. To address this issue and gain deeper insights into the neural mechanisms underlying nicotine dependence, this study proposes a novel graph neural network framework, termed TI-GNN. This model leverages functional magnetic resonance imaging (fMRI) data to identify complex and subtle abnormalities in brain connectivity patterns associated with smoking addiction. MethodsThe study utilizes fMRI data to construct functional connectivity matrices that represent interaction patterns among brain regions. These matrices are interpreted as graphs, where brain regions are nodes and the strength of functional connectivity between them serves as edges. The proposed TI-GNN model integrates a Transformer module to effectively capture global interactions across the entire brain network, enabling a comprehensive understanding of high-level connectivity patterns. Additionally, a spatial attention mechanism is employed to selectively focus on informative inter-regional connections while filtering out irrelevant or noisy features. This design enhances the model’s ability to learn meaningful neural representations crucial for classification tasks. A key innovation of TI-GNN lies in its built-in causal interpretation module, which aims to infer directional and potentially causal relationships among brain regions. This not only improves predictive performance but also enhances model interpretability—an essential attribute for clinical applications. The identification of causal links provides valuable insights into the neuropathological basis of addiction and contributes to the development of biologically plausible and trustworthy diagnostic tools. ResultsExperimental results demonstrate that the TI-GNN model achieves superior classification performance on the smoking addiction dataset, outperforming several state-of-the-art baseline models. Specifically, TI-GNN attains an accuracy of 0.91, an F1-score of 0.91, and a Matthews correlation coefficient (MCC) of 0.83, indicating strong robustness and reliability. Beyond performance metrics, TI-GNN identifies critical abnormal connectivity patterns in several brain regions implicated in addiction. Notably, it highlights dysregulations in the amygdala and the anterior cingulate cortex, consistent with prior clinical and neuroimaging findings. These regions are well known for their roles in emotional regulation, reward processing, and impulse control—functions that are frequently disrupted in nicotine dependence. ConclusionThe TI-GNN framework offers a powerful and interpretable tool for the objective diagnosis of smoking addiction. By integrating advanced graph learning techniques with causal inference capabilities, the model not only achieves high diagnostic accuracy but also elucidates the neurobiological underpinnings of addiction. The identification of specific abnormal brain networks and their causal interactions deepens our understanding of addiction pathophysiology and lays the groundwork for developing targeted intervention strategies and personalized treatment approaches in the future.
7.Study on improvement effect of Danggui Shaoyao San on edema in rats with nephrotic syndrome and its mechanism
Xiao-Wen MA ; Sheng-Nan FAN ; Zai-Ping XU ; Qing-Zhen XIANG ; Zi-Hua XUAN ; Yun-Lai WANG ; Fan XU
Chinese Pharmacological Bulletin 2024;40(6):1172-1178
Aim To explore the effect of Danggui Shaoyao San on edema in rats with nephrotic syndrome and the underlying mechanism.Methods Rats were randomly divided into control group,model group,Danggui Shaoyao San group(17.2 g·kg-1·d-1),losartan group(30 mg·kg-1·d-1)and tolvaptan group(3 mg·kg-1·d-1).The rat model of nephrot-ic syndrome was established by tail vein injection of adriamycin.After four weeks of treatment,the levels of renal function and 24 h urinary protein were detected.The distribution of aquaporin 2(AQP2)and pS256-AQP2 in renal tissue was detected by immunohisto-chemistry.The levels of plasma arginine vasopressin(AVP)and angiotensin Ⅱ(Ang Ⅱ)were measured by radioimmunoassay.The expressions of renal AQP2,pS256-AQP2,angiotensin type 1 receptor(AT1R),arginine vasopressin receptor 2(V2R)protein and mRNA were measured by Western blot and RT-PCR,respectively.Results The three drugs could improve renal function,reduce proteinuria,decrease plasma AVP and Ang Ⅱ levels,and down-regulate AQP2 and pS256-AQP2 protein and mRNA expression in model rats.Danggui Shaoyao San and tolvaptan were more ef-fective than losartan in reducing plasma AVP levels.Conclusions Danggui Shaoyao San may regulate the expression of AQP2 by reducing the levels of AVP and Ang Ⅱ,and improve the edema of nephrotic syndrome rats.
8.Expression pattern and function of novel gene C12ORF56 in lung cancer
Zeng ZHANG ; Hua-Zhen XU ; Run-He QIN ; Yun-Min HUANG ; Ya-Hao LING ; Wen-Lin CHANG
Chinese Pharmacological Bulletin 2024;40(9):1680-1687
Aim To disclose the subcellular localiza-tion,expression pattern,cellular physiological function and possible molecular mechanism of C12ORF56,a novel gene located at q14.2 of chromosome 12,in the pathogenesis of lung cancer.Methods ONCOMINE database was applied to investigate the mRNA level dif-fering of C12ORF56 between normal and lung cancer tissues.Analysis based on LinkedOmics,Metascape,String and GSEA database or tools provided indication of potential cellular physiological functions of C12ORF56 in the developing of lung cancer.C12ORF56 was knocked down via siRNA and the pro-liferation of NCI-H1073 cells were observed by EdU and CCK-8 assay.RT-qPCR was used to detect the ex-pression level of C12ORF56 of lung cancer cells on dif-ferent cycle phases.The core sequence regions of pro-moter affecting the transcription of C12ORF56 gene were analyzed by Jaspar online-tools and verified by dual-luciferase assay.Results C12ORF56 was highly expressed in lung cancer cells,especially in squamous cell lung cancer.C12ORF56 correlated with cell cy-cle,cancer immune,DNA replication.Knockdown of C12ORF56 reduced NCI-H1703 cell proliferation.Conclusion The up-regulation of C12ORF56 is in-volved in the development of lung cancer by enhancing lung cancer cell proliferation.
9.Effect of Cinobufacini on HepG2 cells based on CXCL5/FOXD1/VEGF pathway
Xiao-Ke RAN ; Xu-Dong LIU ; Hua-Zhen PANG ; Wei-Qiang TAN ; Tie-Xiong WU ; Zhao-Quan PAN ; Yuan YUAN ; Xin-Feng LOU
Chinese Pharmacological Bulletin 2024;40(12):2361-2368
Aim To investigate the impact of Cinobu-facini on the proliferation,invasion,and apoptosis of HepG2 cells and the underlying mechanism.Methods The proliferation of HepG2 cells was assessed using the CCK-8 method following treatment with Cinobufaci-ni.The invasion capability of HepG2 cells was evalua-ted through Transwell assay after exposure to Cinobufa-cini.The apoptosis rates of HepG2 cells post Cinobufa-cini intervention were measured using flow cytometry,and the expression levels of VEGF in the culture medi-um of HepG2 cells were determined using enzyme-linked immunoassay.Furthermore,qRT-PCR and Western blot analyses were conducted to assess the im-pact of Cinobufacini on mRNA and protein expression levels related to the CXCL5/FOXD1/VEGF pathway.The interaction between CXCL5 and FOXD1 was inves-tigated via co-immunoprecipitation.Results Cinobufa-cini treatment led to a gradual decrease in HepG2 cell viability in a dose-dependent manner compared to the control group(P<0.05).Moreover,Cinobufacini sig-nificantly suppressed HepG2 cell invasion(P<0.05)while enhancing cell apoptosis(P<0.05).Notably,Cinobufacini exhibited inhibitory effects on the CX-CL5/FOXD1/VEGF pathway,as evidenced by re-duced expression of related mRNA and proteins(P<0.05).FOXD1 was identified as the binding site of CXCL5.Overexpression of CXCL5 resulted in in-creased proliferation and VEGF secretion by HepG2 cells(P<0.05),and increased expression of FOXD1 and VEGF(P<0.05).However,Cinobufacini inter-vention effectively inhibited liver cancer cell prolifera-tion and invasion(P<0.05),promoted apoptosis(P<0.05),reduced VEGF secretion by HepG2 cells(P<0.05),and downregulated the expression of CXCL5 and FOXD1 in HepG2 cells(P<0.05);but com-pared with the unexpressed group of Cinobufacini,its ability to inhibit cell activity was weakened(P<0.05),and its ability to inhibit the expression of CX-CL5,FOXD1,and VEGF was weakened(P<0.05).Conclusion Cinobufacini may inhibit HepG2 cell pro-liferation and invasion and promote HepG2 cell apopto-sis by regulating the CXCL5/FOXD1/VEGF pathway.
10.Quality control and methodology on rFC detection of bacterial endotoxins in zoledronic acid
Xiaolan ZHEN ; Hua LIU ; Lunan GE ; Hui LI ; Didi XING
Drug Standards of China 2024;25(5):483-488
Objective:To standardize the bacterial endotoxin testing criteria for zoledronic acid injection and estab-lish a detection method using recombinant factor C(rFC).Methods:The gel-clot method(BET)was utilized to test 13 batches of zoledronic acid injection from national supervision and random inspection.Interference tests were conducted on zoledronic acid injections from three manufacturers at different concentrations(500,100,50,25 μg·mL-1)using rFC test kits from two manufacturers.Results:Detection was performed for the specification of 100 mL∶5 mg and other specifications according to<0.50 EU per 1 mL and<5.0 EU per 1 mg,respectively,and all results met the criteria.The recovery rate for 25 μg·mL-1 using rFC kits from both manufacturers ranged between 50%and 200%.Validation of rFC.Methods:Eight batches of zoledronic acid injection were validated at 25 μg·mL-1,five batches of zoledronic acid injection(100 mL∶5 mg)were validated at 0.5 EU·mL-1,and all recovery rates were between 50%and 200%.Conclusion:The bacterial endotoxin testing method for zoledronic acid injection can be established as follows:for large volume injection products with 100 mL or more,each 1 mL should contain less than 0.50 EU of endotoxin(following the Chinese Pharmacopoeia 2020,general chapter 1143).For other specifications,each 1 mg of zoledronic acid should contain less than 10.0 EU of endotoxin.The rFC test kit method for bacterial endotoxins involved diluting the sample with water for bacterial endotoxin testing to contain 25 μg of zoledronic acid per 1 mL,or performing 1∶1 dilution for large volume injections(100 mL∶5.0 mg specifi-cation),with recovery rate between 50%and 200%as per the kit instructions.

Result Analysis
Print
Save
E-mail