scholarly journals Stability of Metronidazole and Its Complexes with Silver(I) Salts under Various Stress Conditions

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3582
Author(s):  
Małgorzata Starek ◽  
Monika Dąbrowska ◽  
Joanna Chebda ◽  
Dominik Żyro ◽  
Justyn Ochocki

Metronidazole is a drug widely used in the prevention and treatment of bacterial infections. Due to its possibility of the formation of stable metal complexes, it was decided to broaden its activity spectrum by introducing the silver(I) coordination compounds i.e., [Ag(MTZ)2NO3] and [(Ag(MTZ)2)2]SO4, which have significant antibacterial properties. The paper presents a description of a new qualitative and quantitative analysis of metronidazole in bulk and possible pharmaceutical preparations by thin-layer chromatography with densitometric detection. Optimal separation conditions were selected, and the analytical procedure was validated according to the ICH guidelines. The obtained data indicate that the method is sufficiently sensitive, precise, and accurate. The stability of the metronidazole solutions obtained from tablets, pure metronidazole, and its silver(I) complexes was tested. The research was carried out in various environments, at different temperatures, in H2O2 solution, and during exposure to radiation (UV, sunlight). The greatest degradation was found in the alkaline environment and at higher temperatures. The silver(I) complexes exhibited relatively high stability under analyzed conditions that are higher than standard metronidazole solutions and tablets. The observations were confirmed by the kinetic and thermodynamic analysis. The described studies of new metronidazole silver(I) complexes increase the potential for their application in infections both in humans and animals.

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Nur Asni Setiani ◽  
Welly Octaviyani ◽  
Syarif Hamdani ◽  
Irma Mardiah

Background: The manufacture of pharmaceutical preparations generally adds surfactants. Microbial biosurfactants can be an alternative because biodegradable and have antibacterial properties.   Objective: This study aimed to examine the biosurfactant activity of Exiguobacterium profundum.Methods: Hemolysis and spreading oil tests were performed as an initial screening. Biosurfactant production was carried out by growing bacteria on oil-enriched media with shaker system for 7 days. Biosurfactant activity can be seen from the emulsification index, while the characterization of biosurfactant were used thin layer chromatography and antibacterial qualitative testing.Results: Exiguobacterium profundum could spread the oil layer and form micelles. The emulsification index on days 0, 1, 3, 5, and 7 showed percentage in sequence 44.83%, 48.28%, 48.28%, 40%, and 43.75%. The result of TLC showed lipopeptide group which is marked with red stain with ninhydrin appearance. Antibacterial testing using Escherichia coli showed the formation of clear zones around the disk paper.Conclusion: The biosurfactant produced by Exigoubacterium profundum can be classified into lipopeptide group which has antibacterial activity against gram-negative.


2020 ◽  
Vol 2 (2) ◽  
pp. 61-68
Author(s):  
Agnina Listya Anggraini ◽  
Ratih Dewi Dwiyanti ◽  
Anny Thuraidah

Infection is a disease caused by the presence of pathogenic microbes, including Staphylococcus aureus and Escherichia coli. Garlic (Allium sativum L.) has chemical contents such as allicin, alkaloids, flavonoids, saponins, tannins, and steroids, which can function as an antibacterial against Staphylococcus aureus and Escherichia coli. This study aims to determine the antibacterial properties of garlic extract powder against Staphylococcus aureus and Escherichia coli. This research is the initial stage of the development of herbal medicines to treat Staphylococcus aureus and Escherichia coli infections. The antibacterial activity test was carried out by the liquid dilution method. The concentrations used were 30 mg/mL, 40 mg/mL, 50 mg/mL, 60 mg/mL and 70 mg/mL. The results showed that the Minimum Inhibitory Concentration (MIC) against Staphylococcus aureus and Escherichia coli was 40 mg/mL and 50 mg / mL. Minimum Bactericidal Concentration (MBC) results for Staphylococcus aureus and Escherichia coli are 50 mg/mL and 70 mg/mL. Based on the Simple Linear Regression test, the R2 value of Staphylococcus aureus and Escherichia coli is 0.545 and 0.785, so it can be concluded that there is an effect of garlic extract powder on the growth of Staphylococcus aureus and Escherichia coli by 54.5% and 78.5%. Garlic (Allium sativum L.) extract powder has potential as herbal medicine against bacterial infections but requires further research to determine its effect in vivo.


2020 ◽  
Vol 17 (1) ◽  
pp. 71-84
Author(s):  
Riham M. Bokhtia ◽  
Siva S. Panda ◽  
Adel S. Girgis ◽  
Hitesh H. Honkanadavar ◽  
Tarek S. Ibrahim ◽  
...  

Background: Bacterial infections are considered as one of the major global health threats, so it is very essential to design and develop new antibacterial agents to overcome the drawbacks of existing antibacterial agents. Method: The aim of this work is to synthesize a series of new fluoroquinolone-3-carboxamide amino acid conjugates by molecular hybridization. We utilized benzotriazole chemistry to synthesize the desired hybrid conjugates. Result: All the conjugates were synthesized in good yields, characterized, evaluated for their antibacterial activity. The compounds were screened for their antibacterial activity using methods adapted from the Clinical and Laboratory Standards Institute. Synthesized conjugates were tested for activity against medically relevant pathogens; Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27856) Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 19433). Conclusion: The observed antibacterial experimental data indicates the selectivity of our synthesized conjugates against E.Coli. The protecting group on amino acids decreases the antibacterial activity. The synthesized conjugates are non-toxic to the normal cell lines. The experimental data were supported by computational studies.


2020 ◽  
Vol 16 (4) ◽  
pp. 456-464
Author(s):  
Danilo F. Rodrigues ◽  
Hérida R.N. Salgado

Background: A simple, eco-friendly and low-cost Infrared (IR) method was developed and validated for the analysis of Cefepime Hydrochloride (CEF) in injectable formulation. Different from some other methods, which employ organic solvents in the analyses, this technique does not use these types of solvents, removing large impacts on the environment and risks to operators. Objective: This study aimed at developing and validating a green analytical method using IR spectroscopy for the determination of CEF in pharmaceutical preparations. Methods: The method was validated according to ICH guidelines and the quantification of CEF was performed in the spectral region absorbed at 1815-1745 cm-1 (stretching of the carbonyl group of β- lactam ring). Results: The validated method showed to be linear (r = 0.9999) in the range of 0.2 to 0.6 mg/pellet of potassium bromide, as well as for the parameters of selectivity, precision, accuracy, robustness and Limits of Detection (LOD) and Quantification (LOQ), being able to quantify the CEF in pharmaceutical preparations. The CEF content obtained by the IR method was 103.86%. Conclusion: Thus, the method developed may be an alternative in the quality control of CEF sample in lyophilized powder for injectable solution, as it presented important characteristics in the determination of the pharmaceutical products, with low analysis time and a decrease in the generation of toxic wastes to the environment.


2020 ◽  
Vol 16 ◽  
Author(s):  
Rajendra Muljibhai Kotadiya ◽  
Foram Narottambhai Patel

Background: Rifampicin (RIF), also known as rifampin, a bactericidal antibiotic having broad antibacterial activity against various gram-positive and gram-negative bacteria act by inhibiting DNA dependent RNA polymerase. RIF has been administered in different dosage forms like tablets, capsules, injections, oral suspension, powder etc. for the treatment of several types of bacterial infections, including tuberculosis, Mycobacterium avium complex, leprosy and Legionnaires’ disease. Introduction: To ensure the quality, efficacy, safety and effectiveness of RIF drug product, effective and reliable analytical methods are utmost important. To quantify RIF for quality control or pharmacokinetic purposes, alternative analytical methods have been developed along with the official compendial methods. Method: In this review paper, an extensive literature survey was done to gather information on various analytical instrumental methods used so far for RIF. Result: These methods were high-performance liquid chromatography (42%), hyphenated techniques (18%), spectroscopy (15%), high-performance thin-layer chromatography or thin-layer chromatography (7%) and miscellaneous (18%). Conclusion: All these methods were selective and specific for the RIF analysis.


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 708
Author(s):  
Żaneta Binert-Kusztal ◽  
Małgorzata Starek ◽  
Joanna Żandarek ◽  
Monika Dąbrowska

Currently, there is still a need for broad-spectrum antibiotics. The new cephalosporin antibiotics include, among others, ceftobiprole, a fifth-generation gram-positive cephalosporin, active against Staphylococcus aureus methicillin agonist (MRSA). The main focus of the work was to optimize the conditions of ceftobiprole qualitative determination and to validate the developed procedure according to ICH guidelines. As a result of the optimization process, HPTLC Cellulose chromatographic plates as a stationary phase and a mixture consisting of ethanol:2-propanol: glacial acetic acid: water (4:4:1:3, v/v/v/v) as a mobile phase were chosen. The densitometric detection was carried out at maximum absorbance of ceftobiprole (λ = 232 nm). Next, the validation process of the developed procedure was carried out. The relative standard deviation (RSD) for precision was less than 1.65%, which proves the high compatibility of the results, as well as the LOD = 0.0257 µg/spot and LOQ = 0.0779 µg/spot values, which also confirm the high sensitivity of the procedure. The usefulness of the developed method for the stability studies of ceftobiprole was analyzed. Study was carried out under stress conditions, i.e., acid and alkaline environments, exposure to radiation imitating sunlight and high temperature (40–60 °C). It was found that cefotbiprole is unstable in an alkaline environment and during exposure to UV-VIS radiation. Moreover, the lipophilicity parameter, as a main physicochemical property of the biologically active compound, was determined using experimental and computational methods.


1971 ◽  
Vol 125 (4) ◽  
pp. 1009-1018 ◽  
Author(s):  
R. E. Chambers ◽  
J. R. Clamp

The stability of monosaccharides in methanolic hydrochloric acid of different strengths and at different temperatures was determined. They are generally stable for 24h in methanolic 1m- and 2m-hydrochloric acid at both 85°C and 100°C, but undergo considerable destruction in methanolic 4m- and 6m-hydrochloric acid at 100°C. Analysis of glycopeptides and oligosaccharides of known composition showed that release of carbohydrate was complete within 3h in methanolic 1m-hydrochloric acid at 85°C. Removal of methanolic hydrochloric acid by rotary evaporation resulted in considerable losses of monosaccharides, which could be prevented by prior neutralization. Methanolysis caused extensive de-N-acetylation of acetamidohexoses, so that a re-N-acetylation step is necessary in the analytical procedure. The addition of acetic anhydride for this purpose also prevented loss of internal standard by adsorption on the insoluble silver salts used in neutralization. Several trimethylsilylating agents were studied and suitable conditions are recommended. The effects on the analytical system of water and some common organic and inorganic contaminants are assessed.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 52
Author(s):  
Atanu Naskar ◽  
Sohee Lee ◽  
Kwang-sun Kim

Antibiotic therapy is the gold standard for bacterial infections treatment. However, the rapid increase in multidrug-resistant (MDR) bacterial infections and its recent use for secondary bacterial infections in many COVID-19 patients has considerably weakened its treatment efficacy. These shortcomings motivated researchers to develop new antibacterial materials, such as nanoparticle-based antibacterial platform with the ability to increase the chances of killing MDR strains and prevent their drug resistance. Herein, we report a new black phosphorus (BP)-based non-damaging near-infrared light-responsive platform conjugated with ZnO and Au nanoparticles as a synergistic antibacterial agent against Staphylococcus aureus species. First, BP nanosheets containing Au nanoparticles were assembled in situ with the ZnO nanoparticles prepared by a low-temperature solution synthesis method. Subsequently, the antibacterial activities of the resulting Au–ZnO–BP nanocomposite against the non-resistant, methicillin-resistant, and erythromycin-resistant S. aureus species were determined, after its photothermal efficacy was assessed. The synthesized nanocomposite exhibited excellent anti-S. aureus activity and good photothermal characteristics. The non-resistant S. aureus species did not produce drug-resistant bacteria after the treatment of multiple consecutive passages under the pressure of the proposed nanoantibiotic, but rapidly developed resistance to erythromycin. This work clearly demonstrates the excellent photothermal antibacterial properties of Au–ZnO–BP nanocomposite against the MDR S. aureus species.


Author(s):  
Josep Miquel Bauça ◽  
Andrea Caballero ◽  
Carolina Gómez ◽  
Débora Martínez-Espartosa ◽  
Isabel García del Pino ◽  
...  

AbstractObjectivesThe stability of the analytes most commonly used in routine clinical practice has been the subject of intensive research, with varying and even conflicting results. Such is the case of alanine aminotransferase (ALT). The purpose of this study was to determine the stability of serum ALT according to different variables.MethodsA multicentric study was conducted in eight laboratories using serum samples with known initial catalytic concentrations of ALT within four different ranges, namely: <50 U/L (<0.83 μkat/L), 50–200 U/L (0.83–3.33 μkat/L), 200–400 U/L (3.33–6.67 μkat/L) and >400 U/L (>6.67 μkat/L). Samples were stored for seven days at two different temperatures using four experimental models and four laboratory analytical platforms. The respective stability equations were calculated by linear regression. A multivariate model was used to assess the influence of different variables.ResultsCatalytic concentrations of ALT decreased gradually over time. Temperature (−4%/day at room temperature vs. −1%/day under refrigeration) and the analytical platform had a significant impact, with Architect (Abbott) showing the greatest instability. Initial catalytic concentrations of ALT only had a slight impact on stability, whereas the experimental model had no impact at all.ConclusionsThe constant decrease in serum ALT is reduced when refrigerated. Scarcely studied variables were found to have a significant impact on ALT stability. This observation, added to a considerable inter-individual variability, makes larger studies necessary for the definition of stability equations.


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