Impurity assessment, development and validation of an RP-HPLC method for the determination of eleven potential impurities of eltrombopag precursor.

Eltrombopag is an oral non-peptide thrombopoietin receptor (TPO-R) agonist indicated for the treatment of thrombocytopenia in patients with persistent or chronic immune thrombocytopenia (idiopathic thrombocytopenic purpura, ITP) or chronic hepatitis C infection and the treatment of severe aplastic anemia. The purpose of this research was to assess the possible impurities that may carry over to eltrombopag from its precursor Eltro-1 (3'-amino-2'-hydroxy-[1,1'-biphenyl]-3-carboxylic acid) and to develop a specific analytical method for the determination of these impurities. Eltro-1 samples synthesized by two different synthesis routes were investigated during the evaluation and method development studies. Besides the expected process-related impurities (Eltro-1A - Eltro-1J), e.g., starting materials, intermediates, and/or compounds formed from their further reactions, an unknown impurity detected above 0.10% was identified by LC-MS, synthesized and fully characterized by NMR, MS and FTIR (Eltro-1K). Accordingly, an HPLC-RP method for the determination of eleven impurities (Eltro-1A - Eltro-1K) in Eltro-1 was developed and validated according to ICH Q2. The control limits for impurities in Eltro-1 were set at ≤ 0.15% for Eltro-1A - Eltro-1J and ≤ 1.0% for Eltro-1K based on fate, spike-purge and carryover studies and in accordance with the ICH M7 classification for impurities in drug substance. Eltro-1 and eleven impurities at the specification limit were separated from each other and the diluent peaks with sufficient resolution without interference. Separation was performed on a Waters XBridge C18 column (150 × 4.6 mm, 3.5 µm) at 40 °C with a 10 µL injection volume at a detection wavelength of 220 nm and 15 °C sample temperature. The gradient elution is performed at a flow rate of 1.0 mL/min for 40 min with mobile phase A (0.1% orthophosphoric acid in water) and B (acetonitrile) according to the following program: Time (min) / Acetonitrile (%): 0/0, 35/70, 36/0, 40/0. Test and standard solutions were prepared at a concentration of 1.0 mg/mL and 1.0 µg/mL, respectively, using a mixture of mobile phase A and acetonitrile (75/25) as diluent. This is the first specific, selective, sensitive, linear, precise, accurate, and robust HPLC method for the determination of Eltro-1A - Eltro-1K in Eltro-1, which showed no significant degradation under thermal stress, photostability (UV and VIS), and standard accelerated and long-term stability conditions.

HPLC and LC-MS/MS-Based Quantitative Characterization of Related Substances Associated with Sotalol Hydrochloride.

In total, three related substances (RS) associated with sotalol hydrochloride (STHCl) were herein identified with a novel gradient high-performance liquid chromatography (HPLC) protocol. Further characterization of these substances was then performed via liquid chromatography-mass spectroscopy (LC-MS/MS) and nuclear magnetic resonance (NMR) approaches. For these analyses, commercial STHCl samples were used for quantitative HPLC studies and the degradation of STHCl under acidic (1M HCl), alkaline (1M NaOH), oxidative (30% H2O2), photolytic (4500 Lx), and thermal stress conditions (100 °C) was assessed. This approach revealed this drug to be resistant to acidic, alkaline, and high-temperature conditions, whereas it was susceptible to light and oxidation as confirmed through long-term experiments. The putative mechanisms governing RS formation were also explored, revealing that RS3 was derived from the manufacturing process, whereas RS2 was generated via oxidation and RS1 was generated in response to light exposure. The cytotoxicity of these RS compounds was then assessed using MTT assays and acute toxicity test. Overall, this study provides details regarding the characterization, isolation, quantification, and toxicological evaluation of STHCl and associated RS compounds together with details regarding the precise, specific, and reliable novel HPLC technique, thus providing the requisite information necessary to ensure STHCl purity and safety.

Development and validation of a stability-indicating ultra-high-performance liquid chromatography method for the estimation of ibrutinib and trace-level quantification of related substances using quality-by-design approach.

A new ultra-high-performance liquid chromatography method was developed using quality-by-design principles for quantifying trace-level impurities of ibrutinib. The method utilized an ACQUITY UPLC BEH C18 column with a mobile phase consisting of equal parts of 0.02 M formic acid in water and 0.02 M formic acid in acetonitrile. The critical method parameters, including mobile phase pH, column temperature, and flow rate, were optimized using the design of experiments. Statistical analysis revealed the impact of these parameters on critical quality attributes. Perturbation and response surface plots illustrated the individual and interactive effects of the parameters. The optimal parameter levels were determined to be pH, 2.5; column temperature, 28°C; and flow rate, 0.55 mL/min. Confirmation experiments demonstrated the method's robustness, with the separation of impurities and unknown degradation products within a 5-min runtime. The optimized ultra-performance liquid chromatography method was validated according to ICH guidelines. The method exhibited linear response within the range of 0.025-100 µg/mL for ibrutinib and 0.0187-0.225 µg/mL for impurities (r2 > 0.9995), with limits of detection/limits of quantification of 0.01/0.025 and 0.015/0.0187 for ibrutinib and four impurities, respectively. Recoveries for the drug and impurities ranged from 92.69 to 102.7%, and precision was below 2% and 8% relative standard deviation for ibrutinib and impurities, respectively.

Structural identification of the related substances in phloroglucinol injection by two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry / 药学学报

This study aimed to identify the related substances of phloroglucinol injection by two-dimensional liquid chromatography quadrupole time-of-flight mass spectrometry (2D-LC-Q-TOF/MS). The first-dimensional separation was carried out on an HSS T3 (250 mm × 4.6 mm, 5 μm) column by gradient elution using 1.36 g·L-1 potassium dihydrogen phosphate buffer solution (pH adjusted to 3.0 with diluted phosphoric acid) and acetonitrile as the mobile phases. The separated components were then trapped in switch valve tube lines respectively and delivered to the second-dimensional desalting gradient elution which was performed with a BDS C18 (100 mm × 4.6 mm, 2.4 μm) column using 0.1% formic acid and methanol as the mobile phases. After rapid desalting, electrospray-ionization quadrupole time-of-flight high resolution mass spectrometry was used for determining the accurate masses and elemental compositions of the parents and their product ions for both phloroglucinol and its related substance. Structures of the related substances were then figured out by mass spectrometry elucidation, organic reaction mechanism analysis, and/or comparison with reference substances. Under the established analytical conditions, phloroglucinol and its related substances were adequately separated, 17 main related substances were detected and identified in the injection and its stressed samples for the first time. The identification results can provide reference for the quality control of phloroglucinol injection.

Study on the Dynamic Changes in Non-Volatile Metabolites of Rizhao Green Tea Based on Metabolomics.

The processing of tea leaves plays a crucial role in the formation of the taste of the resulting tea. In order to study the compositions of and changes in taste-related substances during the processing of Rizhao green tea, non-targeted metabolomics was used, based on UHPLC-Q Exactive MS. Totals of 529, 349, and 206 non-volatile metabolites were identified using three different detection modes, of which 112 secondary metabolites were significantly changed. Significant variations in secondary metabolites were observed during processing, especially during the drying stage, and the conversion intensity levels of non-volatile metabolites were consistent with the law of "Drying > Fixation > Rolling". The DOT method was used to screen tea-quality-related compounds that contributed significantly to the taste of Rizhao green tea, including (-)-epicatechin gallate, (-)-epicatechin gallate, gallic acid, L-theanine, and L-leucine, which make important contributions to taste profiles, such as umami and bitterness. Metabolic pathway analysis revealed that purine metabolism, caffeine metabolism, and tyrosine metabolism perform key roles in the processing of Rizhao green tea in different processing stages. The results of this study provide a theoretical basis for tea processing and practical advice for the food industry.

Quality by design-guided development of a capillary electrophoresis method for the simultaneous chiral purity determination and impurity profiling of tamsulosin.

Analytical Quality by Design principles using the design of experiments were applied for the development of a capillary electrophoresis method for the determination of enantiomeric purity and chemically related impurities of tamsulosin. From initial scouting experiments, a dual cyclodextrin (CD) system composed of sulfated ß-CD and carboxymethyl-α-CD was selected as the chiral selector. A fractional factorial resolution V+ design was used for the identification of the critical process parameters, while a face-centered central composite design and Monte Carlo simulations were employed for final optimization and defining the design space of the method. The experimental conditions of the working point were: 30 mM sodium phosphate buffer, pH 3.0, containing 40 mg/mL sulfated ß-CD and 7 mg/mL carboxymethyl-α-CD, capillary temperature 18°C, applied voltage -23 kV. Following the assessment of robustness by applying a Plackett-Burman design, the method was validated according to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use guideline Q2(R1). The method allowed the quantification of the chiral impurity and three other related impurities at the 0.1 % level with acceptable accuracy and precision.

The Applicability of Chromatographic Retention Modeling on Chiral Stationary Phases in Reverse-Phase Mode: A Case Study for Ezetimibe and Its Impurities.

Mechanistic modeling is useful for predicting and modulating selectivity even in early chromatographic method development. This approach is also in accordance with current analytical quality using design principles and is highly welcomed by the authorities. The aim of this study was to investigate the separation behavior of two different types of chiral stationary phases (CSPs) for the separation of ezetimibe and its related substances using the mechanistic retention modeling approach offered by the Drylab software (version 4.5) package. Based on the obtained results, both CSPs presented with chemoselectivity towards the impurities of ezetimibe. The cyclodextrin-based CSP displayed a higher separation capacity and was able to separate seven related substances from the active pharmaceutical ingredient, while the cellulose-based column enabled the baseline resolution of six impurities from ezetimibe. Generally, the accuracy of predicted retention times was lower for the polysaccharide CSP, which could indicate the presence of additional secondary interactions between the analytes and the CSP. It was also demonstrated that the combination of mechanistic modeling and an experimental design approach can be applied to method development on CSPs in reverse-phase mode. The applicability of the methods was tested on spiked artificial placebo samples, while intraday and long-term (2 years) method repeatability was also challenged through comparing the obtained retention times and resolution values. The results indicated the excellent robustness of the selected setpoints. Overall, our findings indicate that the chiral columns could offer orthogonal selectivity to traditional reverse-phase columns for the separation of structurally similar compounds.

An interlaboratory study to evaluate the utility of gas chromatography-mass spectrometry and gas chromatography-infrared spectroscopy spectral libraries in the forensic analysis of fentanyl-related substances.

Synthetic opioids such as fentanyl account for over 71,000 of the approximately 107,000 overdose deaths reported in the United States in 2021. Fentanyl remains the fourth most identified drug by state and local forensic laboratories, and the second most identified drug by federal laboratories. The unambiguous identification of fentanyl-related substances (FRS) is challenging due to the absence or low abundance of a molecular ion in a typical gas chromatography-mass spectrometry (GC-MS) analysis and due to a low number of fragment ions that are similar among the many potential isomers of FRS. This study describes the utility of a previously reported gas chromatography-infrared (GC-IR) library for the identification of FRS within a blind, interlaboratory study (ILS) involving seven forensic laboratories. Twenty FRS reference materials, including those with isomer pairs in the library, were selected based on either their presence in the NIST library and/or some similarity of the mass spectra information produced. The ILS participants were requested to use the Florida International University (FIU) GC-MS and GC-IR libraries supplied by FIU to search for matches to their unknown spectra generated from in-house GC-MS and GC-IR analysis. The laboratories reported improvement in the positive identification of unknown FRS from ~75% using GC-MS alone to 100% correct identification using GC-IR analysis. One laboratory participant used solid phase IR analysis, which produced spectra incompatible with the vapor phase GC-IR library to generate a good comparison spectrum. However, this improved when searched against a solid phase IR library.

Quantitative determination of related substances for Lamotrigine extended release tablet by RP-HPLC.

Lamotrigine extended release tablet dosage form LAMICTAL XR used as an anticonvulsant in the treatment of generalized tonic clonic, absence seizures and partial seizures. The objective of the present study is to develop and validate analytical method for the estimation of related substances in the LAMICTAL XR from GSK; however it is very important to have simple, sensitive, robust and validated analytical method. Hence a precise RP-HPLC analytical method developed for the determination of Related substances in LAMICTAL XR tablet dosage form with gradient elution pattern having mobile phase A as buffer pH 8.0 and mobile phase B as an Acetonitrile at 1.5 mL/min flowrate, using Hypersil BDS C18 column, ambient column temperature and PDA detector with wavelength 220 nm. The analytical method is validated as per ICH guidelines including its forced degradation studies. The method was found to be linear in the range of 0.2 ppm to 2.5 ppm with correlation coefficient 0.999. Accuracy performed at LOQ to 250% level and recovery was found to be in the range of 95% to 105%. Therefore the developed related substances method provides a safe, easy and reproducible for the stability studies and QC release testing for the estimation of related substances.

Development and Validation of SI/RS-UHPLC-PDA Method for Olmesartan Medoxomil and Metoprolol Succinate-Related Substance.

Objectives: Olmesartan medoxomil (OLM) and metoprolol succinate (MPS) in fixed-dose combination (FDC) tablet formulation prescribed extensively. Stability indicating (SI) method for impurities and related substance (RS) test quantitates the amount of these analytes in formulation; the manuscript presents SI/RS-ultra-high performance liquid chromatography-photodiode array (UHPLC-PDA) method for OLM and MPS and their impurities. Materials and Methods: Well-resolved separation of all analytes was achieved with gradient elution on a Shimadzu on Shimpack GIST-C18 (100 mm x 2.1 mm, 2 µm) column maintained at 25°C. Mobile phase-A consist of 0.1% orthophosphoric acid in water and mobile phase-B was acetonitrile at a flow rate of 0.4 mL/min, data integrated at 225 nm and 16 min of short runtime for satisfactory elution of all peaks. Results: The proposed SI/RS-UHPLC-PDA method was developed and validated as per International Conference on Harmonisation (ICH) of Technical Requirements guidelines. The system suitability test complied by all eluted peaks of the interest with acceptable linearity, recovery, and precision. Specificity, robustness, and method sensitivity parameters were determined; all the parameters were found to be within the limits. All the impurities and stress-degraded peaks were well resolved. Conclusion: The proposed method was found to be simple, fast, linear, and accurate. Further, the method is precise, robust, and specific; suitable for routine IPQC during active pharmaceutical ingredient manufacturing, stability and impurity profiling studies of the titled bulk analytes. Furthermore, the method can be extended to assess the levels of impurities formed during life cycle of new FDCs of titled analytes.

Development of HPLC-CAD method for simultaneous quantification of nine related substances in ursodeoxycholic acid and identification of two unknown impurities by HPLC-Q-TOF-MS.

Ursodeoxycholic acid has gained increasing attention due to its recent discovery of the preventive effect on SARS-CoV-2 infection. Ursodeoxycholic acid has been included in various pharmacopoeias as an old drug, and the latest European Pharmacopoeia lists nine potential related substances (impurities A∼I). However, existing methods in pharmacopoeias and literature can only quantify up to five of these impurities simultaneously, and the sensitivity is inadequate, as the impurities are isomers or cholic acid analogues lacking chromophores. Herein, a novel gradient RP-HPLC method coupled to charged aerosol detection (CAD) was developed and validated for the simultaneous separation and quantification of the nine impurities in ursodeoxycholic acid. The method proved sensitive and allowed the quantification of the impurities as low as 0.02 %. Relative correction factors of the nine impurities were all within the range of 0.8-1.2 in the gradient mode by optimizing chromatographic conditions and CAD parameters. In addition, this RP-HPLC method is fully compatible with LC-MS due to the volatile additives and high percentage of the organic phase, which can be directly used for the identification of impurities. The newly developed HPLC-CAD method was successfully applied to commercial bulk drug samples, and two unknown impurities were identified by HPLC-Q-TOF-MS. The effect of CAD parameters on the linearity and correction factors was also discussed in this study. Overall, the established HPLC-CAD method can improve the methods in current pharmacopoeias and literature and contributes to understanding the impurity profile for process improvement.

Development and validation of apalutamide-related substances method in solid dosage forms using HPLC.

A related-substances method was developed for the anticancer drug formulation apalutamide 60 mg tablets and validated using a liquid chromatography gradient elution method. All of the impurities and degradants were separated using the Luna Omega 5 µm Polar C18 , (250 × 4.6) mm HPLC column with a 1.0 ml min-1 flow rate. The detection was done at 225 nm by injecting the 10 µl of injection volume, controlling the sample temperature at 10°C and maintaining the column compartment temperature at 30°C. The total run time was 85 min. A 0.01 m disodium phosphate dihydrate pH 4.20 ± 0.05 buffer mixed with acetonitrile in the ratio of 73:27 (v/v) was used as mobile phase A. Mobile phase B consisted of water and acetonitrile in the ratio 30:70 (v/v). The proposed method was validated as per the current regulatory guidelines. The method precisions (RSD) at 100% specification level were 1.41, 1.74, 1.84, and 1.66% for the four impurities. The accuracy results were obtained between 96.0 and 106.3% for the limit of quantitation to the 150% level. The standard and sample solutions stability were established for 44 h at 10°C. The correlation coefficient (r) value was >0.999 for all four impurities, indicating good linearity between the concentration and peak response: 0.9999, 0.9999, 0.9999 and 1.0000. These results show the method's linearity. The three filter compatibility was proved and it was concluded that 0.45 µm Nylon, PTFE and PVDF filters are suitable. The robustness of the method was established by varying the conditions. The method specificity was proved and the forced degradation data reveal the method's stability-indicating nature.

Analysis method optimization and stability test of related substances of chloral hydrate / 药学实践杂志

Objective To establish a quality control method for detecting impurities in chloral hydrate raw materials, improve the quality standards and control limits of raw materials. Methods The determination methods of chloroform and halogenated carboxylic acid in chloral hydrate were established to monitor the change of impurities in chloral hydrate through stability. Results The research and establishment of chloroform and halogenated carboxylic acid methods met the requirements of relevant regulations for analytical methodology verification, which could accurately detect four impurities in raw materials and preparations by one method. Conclusion The study provides technical support for the improvement and optimization of the quality standards of chloral hydrate and preparations. It is very necessary to implement the impurity monitoring in preparation research and production process by the chloral hydrate impurity detection and the stability comparison of this product at high temperature and light, which could largely promote the safety of medication.

Determination of related substances in egg yolk lecithin by HPLC-CAD and characterization of its profiling by HPLC-Q-TOF-MS.

A high-performance liquid chromatography (HPLC) method has been developed for the determination of related substances in egg yolk lecithin. Chromatographic separation was achieved using a gradient elution on a Waters Xbridge HILIC column maintained at 35 â„ƒ. Mobile phase A was composed of water-acetonitrile (80:20, v/v, containing 5 mM ammonium acetate), and mobile phase B was composed of acetonitrile. Analytes were monitored by a charged aerosol detector (CAD) at 50 â„ƒ. The novel HPLC-CAD method was selective and sensitive for the determination of related substances in egg yolk lecithin in its commercial bulk batches. It was also successfully validated by the International Council for Harmonisation (ICH) guidelines. The method will be a renewal of an old Chinese Pharmacopoeia method (2020 edition). Moreover, quadrupole time-of-flight mass spectrometry (Q-TOF-MS) was integrated with HPLC to investigate phospholipid species in egg yolk lecithin. This work provides comprehensive composition profiles of egg yolk lecithin, thereby accelerating the quality control, development, and application of egg yolk lecithin.

[Cognition innovation of toxicity of Chinese medicine and safe and precise medication].

Traditional Chinese medicine(TCM) has made outstanding contributions to disease prevention and treatment, survival, and reproduction of the Chinese nation. Currently, the inheritance and innovative development of TCM have become a national strategy. However, in recent years, adverse reactions/events of Chinese medicine frequently occurred. In particular, in terms of the safety problem of newly discovered "toxic" Chinese medicine, it is often difficult to answer the question scientifically and develop effective solutions. When facing international public opinions and public questioning, they are often "passively criticized". To solve the difficult problem about the safety of Chinese medicine, we urgently need to make breakthroughs in the cognition of toxicity of Chinese medicine and prevention and control of risks. This research team has been committed to the research on the safety of Chinese medicine for the long term. In particular, in terms of safety evaluation and risk prevention and control of newly discovered "toxic" Chinese medicine, they have made a series of original discoveries. On the basis of the discoveries, they innovated the cognition theory and methods of the toxicity of Chinese medicine, opened up a new field of research on the idiosyncratic toxicity and indirect toxicity of Chinese medicine, and proposed and established the disease-syndrome-based toxicology(DSBT), the model and method of safety evaluation of Chinese medicine related to diseases and syndromes. In light of the theory and methods of DSBT which have been applied to the objective eva-luation and analysis of the mechanism of the hepatotoxicity of Chinese medicine such as Polygoni Multiflori Radix, the mechanism hypothesis of "toxicity due to three causes" of idiosyncratic hepatotoxicity of Chinese medicine was proposed and confirmed. The findings revealed that the substances that induced idiosyncratic or indirect toxicity in Chinese medicine often did not possess definite direct toxi-city. Therefore, this research team proposed the concept of toxicity-related substances(TRS) in Chinese medicine. Based on the mo-dern scientific cognition of toxicity of Chinese medicine, the team proposed the strategy and method of Chinese medicine compatibility to reduce the toxicity based on the component-effect-target interaction to underpin the demonstration of the scientific connotation of toxicity and side effects of "toxic" Chinese medicine and establishment of scientific and effective risk prevention and control strategies. In light of the innovative development of toxicity cognition of Chinese medicine, this study is expected to provide important theoretical guidance and methodological support for scientific evaluation and precise prevention and control of the safety risk of "toxic" Chinese medicine.

A full-scale tracing study of "ghost peaks" encountered in impurity analysis of budesonide based on experimental operation inspection-liquid chromatography/mass spectrometry fingerprint-mechanism based stress studies integrated strategy.

Budesonide is an active pharmaceutical ingredient used in various dosage forms of finished products for the treatment of asthma. During the process of drug development, unbiased analysis of related substances is of utmost significance for both pharmaceutical research and quality control purposes. In this work, the official method documented in the United States Pharmacopoeia was selected to determine the related substances of budesonide considering the pros and cons of critical chromatographic parameters, compared to the European Pharmacopoeia. In doing so, several unpredictable interference peaks, namely "ghost peaks", were observed occasionally during analysis. A strategy that integrated information derived from experimental operation inspection, liquid chromatography/mass spectrometry fingerprint analysis, and mechanism-based stress studies was then proposed for comprehensively and quickly exploring those non-degradable and degradable peaks. Some ghost peaks were found to originate from nylon syringe filter, illumination, and alkali borosilicate glass high-performance liquid chromatography vials. Besides, degradation pathways under alkaline conditions were also unraveled through liquid chromatography-mass spectrometry qualitative analysis. Overall, an optimization of the analytical methodology based on the United States Pharmacopoeia for its application in impurity analysis of budesonide and corresponding formulations was carried out with the design of experiments, by which "ghost peaks" could be suppressed or prevented. The results obtained herein are not only crucial to studies on budesonide's stability or degradation kinetics but also contribute to clarifying the impurity research of other drugs.

Heparin and Related Substances for Treating Diabetic Foot Ulcers: A Systematic Review and Meta-Analysis.

Background: Diabetic foot ulcers are a major complication of diabetes mellitus (DM), when heparin and heparin related substances may be potentially used as an adjuvant treatment. We aimed to evaluate the efficacy and safety of heparin and heparin related substances for the treatment of diabetic foot ulcers. Methods: We searched up to March 2021 in the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; EBSCO CINAHL; VIP Chinese Science and Technique Journals Database; China National Knowledge Infrastructure (CNKI) Database and Wan Fang Database investigating heparin or heparin-related substances in patients with diabetic foot ulcers. The primary outcomes included proportion of ulcers completely healed and time to complete ulcer healing. We assessed each included study with the Cochrane 'Risk of bias' tool and used the GRADE approach to assess the overall quality of the evidence. Results: We included nine randomized studies involving 620 participants in the meta-analysis, involving two different heparin and heparin-related substances, low molecular weight heparin (LMWH) and hyaluronic acid. Our study did not show the benefits from LMWH on increasing chance of the ulcer healing (RR: 1.26; 95% CI: 0.78 to 2.04; P=0.35; very low) or shortening the time to complete ulcer healing (SMD: 0.13 d; 95% CI: -0.29 to 0.56; P=0.54; very low). Hyaluronic acid may improve the complete ulcer healing (RR: 1.57; 95% CI: 1.29 to 1.91; P˂0.00001; very low) and shorten the time to complete ulcer healing (SMD -0.84, 95% CI -1.15 to -0.53; P<0.00001; low). Hyaluronic acid and LMWH were generally well tolerated for treating diabetic foot ulcers in this review. Conclusion: Hyaluronic acid may improve diabetic foot ulcer with very low quality evidence but not LMWH. However, the benefits and harms need further validation in larger trials with different population. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [PROSPERO, CRD42021269212].

Development and validation of a simple and sensitive HPLC method for the determination of related substances in regorafenib tablets.

Regorafenib as an oral multi-kinase inhibitor has displayed a promising future in the anticancer drug market. However, there are no articles reporting the method for the determination of related substances in regorafenib tablets. A quality standard was first included in the Ph. Eur. 10.4 until April 2021 but could not detect seven known impurities A, C, D, E, FP-A, FP-B, and FP-C simultaneously. In this paper, a simple and sensitive HPLC method was established for the determination of related substances in regorafenib tablets. The determination was performed on a Polar-RP column with dual wavelength detection set at 230 nm and 260 nm. This method was validated according to the ICH guidelines. Furthermore, the possible sources of impurities were analyzed and forced degradation tests were performed, which provided guidance for formulation development and storage conditions. The established method is simple, sensitive and accurate for the determination of related substances in regorafenib tablets. A specified and sensitive HPLC method for the determination of related substances in regorafenib tablets.

Favipiravir (SARS-CoV-2) degradation impurities: Identification and route of degradation mechanism in the finished solid dosage form using LC/LC-MS method.

Favipiravir finished dosage was approved for emergency use in many countries to treat SARS-CoV-2 patients. A specific, accurate, linear, robust, simple, and stability-indicating HPLC method was developed and validated for the determination of degradation impurities present in favipiravir film-coated tablets. The separation of all impurities was achieved from the stationary phase (Inert sustain AQ-C18, 250 × 4.6 mm, 5-µm particle) and mobile phase. Mobile phase A contained KH2 PO4 buffer (pH 2.5 ± 0.05) and acetonitrile in the ratio of 98:2 (v/v), and mobile phase B contained water and acetonitrile in the ratio of 50:50 (v/v). The chromatographic conditions were optimized as follows: flow rate, 0.7 mL/min; UV detection, 210 nm; injection volume, 20 µL; and column temperature, 33°C. The proposed method was validated per the current International Conference on Harmonization Q2 (R1) guidelines. The recovery study and linearity ranges were established from the limit of quantification to 150% optimal concentrations. The method validation results were found to be between 98.6 and 106.2% for recovery and r2  = 0.9995-0.9999 for linearity of all identified impurities. The method precision results were achieved below 5% of relative standard deviation. Forced degradation studies were performed in chemical and physical stress conditions. The compound was sensitive to chemical stress conditions. During the study, the analyte degraded and converted to unknown degradation impurities, and its molecular mass was found using the LC-MS technique and established degradation pathways supported by reaction of mechanism. The developed method was found to be suitable for routine analysis of research and development and quality control.

[Efficacy-related substances of blood-activating and stasis-resolving medicinals derived from Curcuma plants: a review].

Derived from Curcuma plants, Curcumae Longae Rhizoma, Curcumae Rhizoma, Wenyujin Rhizoma Concisum, and Curcumae Radix are common blood-activating and stasis-resolving medicinals in clinical practice, which are mainly used to treat amenorrhea, dysmenorrhea, chest impediment and heart pain, and rheumatic arthralgia caused by blood stasis block. According to modern research, the typical components in medicinals derived from Curcuma plants, like curcumin, demethoxycurcumin, bisdemethoxycurcumin, curdione, germacrone, curcumol, and ß-elemene, have the activities of hemorheology improvement, anti-platelet aggregation, anti-thrombosis, anti-inflammation, anti-tumor, and anti-fibrosis, thereby activating blood and resolving stasis. However, due to the difference in origin, medicinal part, processing, and other aspects, the efficacy and clinical application are different. The efficacy-related substances behind the difference have not yet been systematically studied. Thus, focusing on the efficacy-related substances, this study reviewed the background, efficacy and clinical application, efficacy-related substances, and "prediction-identification-verification" research method of blood-activating and stasis-resolving medicinals derived from Curcuma plants, which is expected to lay a theoretical basis for the future research on the "similarities and differences" of such medicinals based on integrated evidence chain and to guide the scientific and rational application of them in clinical practice.