A Simple, Fast, Low Cost, HPLC/UV Validated Method for Determination of Flutamide: Application to Protein Binding Studies

Background: Analysis of drug concentrations in biological fluids is required in clinical sciences for various purposes. Among other biological samples, exhaled breath condensate (EBC) is a potential sample for follow up of drug concentrations. Methods: A dispersive liquid-liquid microextraction (DLLME) procedure followed by a validated liquid chromatography method was employed for the determination of budesonide (BDS) in EBC samples collected using a homemade setup. EBC is a non-invasive biological sample with possible applications for monitoring drug concentrations. The proposed analytical method is validated according to the FDA guidelines using EBC-spiked samples. Its applicability is tested on EBC samples collected from healthy volunteers receiving a single puff of BDS. Results: The best DLLME conditions involved the use of methanol (1 mL) as a disperser solvent, chloroform (200 μL) as an extraction solvent, and centrifugation rate of 3500 rpm for 5 minutes. The method was validated over a concentration range of 21-210 μg·L-1 in EBC. Inter- and intra-day precisions were less than 10% where the acceptable levels are less than 20%. The validated method was successfully applied for the determination of BDS in EBC samples. Conclusion: The findings of this study indicate that the developed method can be used for the extraction and quantification of BDS in EBC samples using a low cost method.

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Development and Validation of an Eco-Friendly and Low-Cost Method for the Quantification of Cefepime Hydrochloride in Powder for Injectable Solution Using Infrared (IR) Spectroscopy

Current Analytical Chemistry ◽

10.2174/1573411014666180704122816 ◽

2020 ◽

Vol 16 (4) ◽

pp. 456-464

Author(s):

Danilo F. Rodrigues ◽

Hérida R.N. Salgado

Keyword(s):

Ir Spectroscopy ◽

Low Cost ◽

Pharmaceutical Preparations ◽

Potassium Bromide ◽

Pharmaceutical Products ◽

Injectable Formulation ◽

Ich Guidelines ◽

Lactam Ring ◽

Development And Validation

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.

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Graphene Modified Molecular Imprinting Electrochemical Sensor for Determining the Content of Dopamine

Current Analytical Chemistry ◽

10.2174/1573411014666180730112304 ◽

2019 ◽

Vol 15 (6) ◽

pp. 628-634

Author(s):

Rong Liu ◽

Jie Li ◽

Tongsheng Zhong ◽

Liping Long

Keyword(s):

Electrochemical Sensor ◽

Molecular Imprinting ◽

Neurological Disorders ◽

Room Temperature ◽

Low Cost ◽

Differential Pulse ◽

Current Response ◽

Specific Selectivity ◽

Pulse Voltammetry

Background: The unnatural levels of dopamine (DA) result in serious neurological disorders such as Parkinson’s disease. Electrochemical methods which have the obvious advantages of simple operation and low-cost instrumentation were widely used for determination of DA. In order to improve the measurement performance of the electrochemical sensor, molecular imprinting technique and graphene have always been employed to increase the selectivity and sensitivity. Methods: An electrochemical sensor which has specific selectivity to (DA) was proposed based on the combination of a molecular imprinting polymer (MIP) with a graphene (GR) modified gold electrode. The performance and effect of MIP film were investigated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV) in the solution of 5.0 ×10-3 mol/L K3[Fe(CN)6] and K4[Fe(CN)6] with 0.2 mol/L KCl at room temperature. Results: This fabricated sensor has well repeatability and stability, and was used to determine the dopamine of urine. Under the optimized experiment conditions, the current response of the imprinted sensor was linear to the concentration of dopamine in the range of 1.0×10-7 ~ 1.0×10-5 mol/L, the linear equation was I (µA) = 7.9824+2.7210lgc (mol/L) with the detection limit of 3.3×10-8 mol/L. Conclusion: In this work, a highly efficient sensor for determination of DA was prepared with good sensitivity by GR and great selectivity of high special recognization ability by molecular imprinting membrane. This proposed sensor was used to determine the dopamine in human urine successfully.

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Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

Analytical Methods ◽

10.1039/c9ay00718k ◽

2019 ◽

Vol 11 (30) ◽

pp. 3866-3873 ◽

Cited By ~ 1

Author(s):

R. Karthikeyan ◽

D. James Nelson ◽

S. Abraham John

Keyword(s):

Glassy Carbon ◽

Low Cost ◽

Phosphate Buffer Solution ◽

Purine Nucleotides ◽

Buffer Solution ◽

Solution Ph ◽

Carbon Dot ◽

Enzymatic Determination ◽

Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

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Using seed respiration as a tool for calculating optimal soaking times for ‘on-farm’ seed priming of barley (Hordeum vulgare)

Seed Science Research ◽

10.1017/s0960258521000039 ◽

2021 ◽

pp. 1-9

Author(s):

Javier Carrillo-Reche ◽

Adrian C. Newton ◽

Richard S. Quilliam

Keyword(s):

Morphological Changes ◽

Low Cost ◽

Germination Rate ◽

Seed Priming ◽

Embryonic Axes ◽

Seedling Vigour ◽

Soaking Time ◽

On Farm ◽

Seed Respiration

Abstract A low-cost technique named ‘on-farm’ seed priming is increasingly being recognized as an effective approach to maximize crop establishment. It consists of anaerobically soaking seeds in water before sowing resulting in rapid and uniform germination, and enhanced seedling vigour. The extent of these benefits depends on the soaking time. The current determination of optimal soaking time by germination assays and mini-plot trials is resource-intensive, as it is species/genotype-specific. This study aimed to determine the potential of the seed respiration rate (an indicator of metabolic activity) and seed morphological changes during barley priming as predictors of the priming benefits and, thus, facilitate the determination of optimal soaking times. A series of germination tests revealed that the germination rate is mostly attributable to the rapid hydration of embryo tissues, as the highest gains in the germination rate occurred before the resumption of respiration. Germination uniformity, however, was not significantly improved until seeds were primed for at least 8 h, that is, after a first respiration burst was initiated. The maximum seedling vigour was attained when the priming was stopped just before the beginning of the differentiation of embryonic axes (20 h) after which vigour began to decrease (‘over-priming’). The onset of embryonic axis elongation was preceded by a second respiration burst, which can be used as a marker for priming optimization. Thus, monitoring of seed respiration provides a rapid and inexpensive alternative to the current practice. The method could be carried out by agricultural institutions to provide recommended optimal soaking times for the common barley varieties within a specific region.

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Ultrafiltration Method for Plasma Protein Binding Studies and Its Limitations

Processes ◽

10.3390/pr9020382 ◽

2021 ◽

Vol 9 (2) ◽

pp. 382

Author(s):

Camelia-Maria Toma ◽

Silvia Imre ◽

Camil-Eugen Vari ◽

Daniela-Lucia Muntean ◽

Amelia Tero-Vescan

Keyword(s):

Protein Binding ◽

Plasma Protein Binding ◽

Plasma Protein ◽

Specific Binding ◽

Critical Role ◽

Volume Ratio ◽

Binding Studies ◽

Experimental Conditions ◽

Key Aspects

Plasma protein binding plays a critical role in drug therapy, being a key part in the characterization of any compound. Among other methods, this process is largely studied by ultrafiltration based on its advantages. However, the method also has some limitations that could negatively influence the experimental results. The aim of this study was to underline key aspects regarding the limitations of the ultrafiltration method, and the potential ways to overcome them. The main limitations are given by the non-specific binding of the substances, the effect of the volume ratio obtained, and the need of a rigorous control of the experimental conditions, especially pH and temperature. This review presents a variety of methods that can hypothetically reduce the limitations, and concludes that ultrafiltration remains a reliable method for the study of protein binding. However, the methodology of the study should be carefully chosen.

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