A rapid Fourier-transform infrared (FTIR) spectroscopic method for direct quantification of paracetamol content in solid pharmaceutical formulations

Delineating acetaminophen biodegradation kinetics and metabolomics using bacterial community

Acetaminophen [N-(4-hydroxyphenyl) acetamide, APAP] is an extensively and frequently consumed over-the-counter analgesic and antiphlogistic medication. It is being regarded as an emerging pollutant due to its continuous increment in the environment instigating inimical impacts on humans and the ecosystem. Considering its wide prevalence in the environment, there is an immense need of appropriate methods for the removal of APAP. The present study indulged screening and isolation of APAP degrading bacterial strains from pharmaceuticals-contaminated sites, followed by their molecular characterization via 16S rRNA sequencing. The phylogenetic analyses assigned the isolates to the genera Pseudomonas, Bacillus, Paracoccus, Agrobacterium, Brucella, Escherichia, and Enterobacter based on genetic relatedness. The efficacy of these strains in batch cultures tested through High-performance Liquid Chromatography (HPLC) revealed Paracoccus sp. and Enterobacter sp. as the most promising bacterial isolates degrading up to 88.96 and 85.92%, respectively of 300 mg L-1 of APAP within 8 days of incubation. Michaelis-Menten kinetics model parameters also elucidated the high degradation potential of these isolates. The major metabolites identified through FTIR and GC-MS analyses were 4-aminophenol, hydroquinone, and 3-hydroxy-2,4-hexadienedioic. Therefore, the outcomes of this comprehensive investigation will be of paramount significance in formulating strategies for the bioremediation of acetaminophen-contaminated sites through a natural augmentation process via native bacterial strains.

Identification and quantification techniques of polymorphic forms - A review

In the pharmaceutical industry, the unexpected appearance of crystalline forms could impact the therapeutic efficacy of an Active Pharmaceutical Ingredient (API). For quality control, a thorough qualitative and quantitative monitoring of pharmaceutical solid forms is essential to ensure the detection and the quantification of crystalline forms, wither different or with the same chemical composition (polymorphs) at a low detection level. The purpose of this paper was to review and highlight the importance of choosing adequate solid-state techniques for detection and quantification APIs that present polymorphism - based on limits of detection (LOD) and quantification (LOQ), pharmacopeias specifications, international guidelines and studies reported in the literature. To this study, the powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), Infrared and Raman spectroscopies and solid-state nuclear magnetic resonance (NMR) were the solid-state techniques analyzed. Additionally, the Argentine, Brazilian, British, European, International, Japanese, Mexican and the United States of America pharmacopeias were reviewed. Based on the analysis performed, the advantages and disadvantages of these techniques, as well as the LOD and LOQ values of APIs were reported. In comparison to these solid-state techniques, reference material used for identification analyses should be previously identified with the corresponding polymorph. Without this previous procedure, the patterns, the spectra, and DSC curves of the reference material can only be used to confirm the mixture of solid forms, not being able to specify which polymorphs are contained in the sample. A major advantage of PXRD is the use of the calculated diffraction patterns obtained from the Crystallographic Information Frameworks (CIFs) files which could be used as a reference pattern without any other information, assistance technique, or physical standards. Regarding the quantification aspect, different pharmacopeias suggest various methods such as the PXRD combining with Rietveld method, which can be used to obtain lower LOD values for minority phases in the mixture of different substances without the need for a calibration curve. Raman spectroscopy can detect polymorphs in small particles and solid-state NMR spectroscopy is a powerful technique for quantification not only crystalline but also crystalline-amorphous mixtures. Finally, this review intends to be a useful tool to control, with efficiency and accuracy, the polymorphism of APIs in pharmaceutical compounds.

Sensitive electrochemical assay of acetaminophen based on 3D-hierarchical mesoporous carbon nanosheets

Acetaminophen plays a key role in first-line Covid-19 cure as a supportive therapy of fever and pain. However, overdose of acetaminophen may give rise to severe adverse events such as acute liver failure in individual. In this work, 3D-hierarchical mesoporous carbon nanosheet (hMCNS) microspheres with superior properties were fabricated using simple and quick strategy and applied for sensitive quantification of acetaminophen in pharmaceutical formulation and rat plasmas after administration. The hMCNS microspheres are prepared via chemical etching of zinc oxide (ZnO) nanoparticles from a zinc-gallic acid precursor composite (Zn-GA) synthesized by high-temperature anaerobic pyrolysis. The obtained hMCNS could enhance analytes accessibility and accelerate proton transfer in the interface, hence increasing the electrochemical performance. Under optimized experimental conditions, the proposed electrochemical sensor achieves a detection limit of 3.5 nM for acetaminophen. The prepared electrochemical sensor has been successfully applied for quantification of acetaminophen in pharmaceutical formulations and the rat plasma samples before and after administration. Meanwhile, this sensor is compared with high-performance liquid chromatography (HPLC) as a reference technology, showing an excellent accuracy. Such an electrochemical sensor has great potential and economic benefits for applications in the fields of pharmaceutical assay and therapeutic drug monitoring (TDM).

Comparison of Vibrational Spectroscopic Techniques for Quantification of Water in Natural Deep Eutectic Solvents

Vibrational spectroscopic techniques, i.e., attenuated total reflectance infrared (ATR-IR), near infrared spectroscopy (NIRS) and Raman spectroscopy (RS), coupled with Partial Least Squares Regression (PLSR), were evaluated as cost-effective label-free and reagent-free tools to monitor water content in Levulinic Acid/L-Proline (LALP) (2:1, mol/mol) Natural Deep Eutectic Solvent (NADES). ATR-IR delivered the best outcome of Root Mean Squared Error (RMSE) of Cross-Validation (CV) = 0.27% added water concentration, RMSE of Prediction (P) = 0.27% added water concentration and mean % relative error = 2.59%. Two NIRS instruments (benchtop and handheld) were also compared during the study, respectively yielding RMSECV = 0.35% added water concentration, RMSEP = 0.56% added water concentration and mean % relative error = 5.13% added water concentration, and RMECV = 0.36% added water concentration, RMSEP = 0.68% added water concentration and mean % relative error = 6.23%. RS analysis performed in quartz cuvettes enabled accurate water quantification with RMECV = 0.43% added water concentration, RMSEP = 0.67% added water concentration and mean % relative error = 6.75%. While the vibrational spectroscopic techniques studied have shown high performance in relation to reliable determination of water concentration, their accuracy is most likely related to their sensitivity to detect the LALP compounds in the NADES. For instance, whereas ATR-IR spectra display strong features from water, Levulinic Acid and L-Proline that contribute to the PLSR predictive models constructed, NIRS and RS spectra are respectively dominated by either water or LALP compounds, representing partial molecular information and moderate accuracy compared to ATR-IR. However, while ATR-IR instruments are common in chemistry and physics laboratories, making the technique readily transferable to water quantification in NADES, Raman spectroscopy offers promising potential for future development for in situ, sample withdrawal-free analysis for high throughput and online monitoring.

Monitoring the water content in NADES extracts from spirulina biomass by means of ATR-IR spectroscopy

Attenuated total reflectance-infrared spectroscopy (ATR-IR) coupled with partial least squares regression (PLSR) was evaluated as a rapid, label free and cost-effective tool to quantify water content in extracts obtained from spirulina wet biomass using a glucose glycerol natural deep eutectic solvent (NADES). NADESs are green, renewable and biodegradable solvents with unique properties outcompeting existing organic solvents, for instance, for plant or biomass extraction. The properties of NADESs depend critically on their water concentration, and therefore, it is essential to develop methods to monitor it, to ensure optimal extraction efficiency and experimental repeatability to achieve a better standardization of extraction protocols. First, Karl Fischer titration was performed on a set of 20 NADES extracts in order to obtain reference water concentrations. Secondly, ATR-IR spectra were collected and subjected to datamining to construct PLSR predictive models. An R² value of 0.9996, a mean root mean square error of cross validation of 0.136% w/w and a root mean square error of prediction of 0.130% w/w highlight the feasibility and reliability to perform quantitative analysis using ATR-IR. Moreover, the mean relative error percentage achieved, ∼0.5%, confirms the high accuracy of water concentration determination in NADES extracts. This work demonstrates that powerful alternatives are available to provide more environmentally responsible analytical protocols. ATR-IR spectroscopy applied to NADES extracts does not require any sample preparation, reagents or solvents and has minimal requirements for single use consumables. The technique is consistent with current concerns to develop greener chemistry, especially in the field of extraction of natural compounds from plants which currently represents a major focus of interest in both research and industry.

Acetaminophen degradation using bacterial strains isolated from winogradsky column and phytotoxicity analysis of dump site soil

The increase in pollution increased the threat level of living organisms in the environment. Municipal Solid Waste is one of the most important wastes which contribute to polluted sites affecting livelihood. They pollute the water stream, marine environment ecology, soil fertility, and agriculture production. This, in turn, reduces the microflora of the marine environment, agricultural soil, and fertility. This could be analyzed by setting up a Winogradsky column using dumpsite soil samples. The current work was designed to study the municipal solid wastes from different dumpsite soil. Soil characterization revealed that the pH of Kodungaiyur and Otteri was 7.3 and 6.4. The bulk density was 0.067 g/cm³ and 0.069 g/cm³. The Porosity resulted to be 0.511 particle/volume and 0.513 particle/volume for Kodungaiyur and Otteri. The Kodungaiyur soil containing contaminants supplied with natural sources showed a 100% germination index, and Otteri soil containing contaminants supplied with natural sources showed a maximum vigour index. The presence of medicinal strips in the collected soil samples led to the study on Acetaminophen degradation. HB1 showed to be 79 ± 0.005% at optimum pH 5 containing 100 mg/L of Acetaminophen at day four among the isolated bacterial strains. Further, the intermediate formation was determined using FTIR and GC-MS. The isolated HB1 bacterial strain was identified as Staphylococcus hominis, which is heterotroph.

FTIR spectroscopic study of two isostructural statins: Simvastatin and Lovastatin as authentic and in pharmaceuticals

A very simple, economic analytical method with few sample pretreatment steps has been developed for quantitation of simvastatin in the presence of its isostructure lovastatin without any interference. It was utilized for easy and complete fine characterization of simvastatin FTIR spectrum from that of lovastatin. Simvastatin has been determined efficiently by the developed method either alone or in mixture with lovastatin giving LOQ values of 0.009 and 0.02% w/w, respectively indicating good sensitivity. Acceptable correlation coefficient values of 0.9975 and 0.9886 alone and in mixture with lovastatin, respectively. The developed spectroscopic method has provided simple and sensitive tool in quality control laboratories for efficient quantitation simvastatin in pharmaceutical tablets with good recoveries.

A chemometric model for the quantitative determination of isotopic impurities in d3-methylamine hydrochloride by Fourier-transform infrared spectroscopy

Deuterated drug molecules are of increasing interest to the pharmaceutical industry due to their capacity to slow metabolism and the potential for improved pharmacokinetics or improved pharmacodynamics they may offer over their non-deuterated counterparts. The desired level of deuteration or isotopic purity is a critical quality attribute for these compounds that can be essential for drug efficacy or patient safety. Deuterated reagents are often used to introduce a deuterated moiety into the drug substance; as such, isotopic impurities in these deuterated input materials need to be tightly controlled. A novel Fourier-transform infrared (FTIR) spectroscopic method was developed and evaluated as a fast and straightforward technique to quantify low-level isotopic impurities in the deuterated reagent d₃-methylamine hydrochloride. Using data acquired through LC-MS analysis, the resulting chemometric model was validated according to ICH Q2(R1) guidelines achieving limits of quantitation of 0.31, 0.31, and 0.34 wt% for d₀-, d₁- and d₂-methylamine hydrochloride impurities respectively.

Electrochemical determination of acetaminophen at a carbon electrode modified in the presence of β-cyclodextrin: role of the activated glassy carbon and the electropolymerised β-cyclodextrin

Acetaminophen is a well-known drug commonly used to provide pain relief, but it can also lead to acute liver failure at high concentrations. Therefore, there is considerable interest in monitoring its concentrations. Sensitive and selective acetaminophen electrochemical sensors were designed by cycling a glassy carbon electrode (GCE) to high potentials in the presence of β-CD in a phosphate electrolyte, or by simply activating the GCE electrode in the phosphate solution. Using cyclic voltammetry, adsorption-like voltammograms were recorded. The acetaminophen oxidation product, N-acetyl benzoquinone imine, was protected from hydrolysis, and this was attributed to the adsorption of acetaminophen at the modified GCE. The rate constants for the oxidation of acetaminophen were estimated as 4.3 × 10–3 cm2 s–1 and 3.4 × 10–3 cm2 s–1 for the β-CD-modified and -activated electrodes, respectively. Using differential pulse voltammetry, the limit of detection was calculated as 9.7 × 10–8 M with a linear concentration range extending from 0.1 to 80 μM. Furthermore, good selectivity was achieved in the presence of caffeine, ascorbic acid and aspirin, enabling the determination of acetaminophen in a commercial tablet. Similar electrochemical data were obtained for both the β-CD-modified and activated GCE surfaces, suggesting that the enhanced detection of acetaminophen is connected mainly to the activation and oxidation of the GCE. Using SEM, EDX and FTIR, no evidence was obtained to indicate that the β-CD was electropolymerised at the GCE.

Observable removal of pharmaceutical residues by highly porous photoactive cellulose acetate@MIL-MOF film

Pharmaceutical products are used tremendously worldwide and subsequently released into wastewater even at very low concentration caused serious environmental problem due to their high activity. Therefore, the present work focuses on remarkable removal of paracetamol as one from the most used pharmaceutical intermediates, by using porous film based on cellulose acetate@metal organic framework (CA@Ti-MIL-NH₂). The film was designed to achieve extreme removal of paracetamol by action of both of adsorption and degradation. Metal organic frame work was directly synthesized and inserted within the pre-prepared porous CA film to obtain porous CA@Ti-MIL-NH₂ film. The synthesized films were applied in adsorption and photo-degradation of paracetamol separately and together. Due to the photocatalytic activity of Ti-MIL-NH_2, the photo-degradation of paracetamol in visible-light was much effective and considerably high degradation of paracetamol was observed (k₁ = 760.0 m^-1) comparing to the adsorption (k₁ = 160.0 m^-1). The overall removal of paracetamol was significantly enlarged from 82.7 mg/g for CA film to 519.1 mg/g for porous CA@Ti-MIL-NH₂ film. The used film exhibited quite good reusability and the removal of paracetamol was lowered from 96% to 85% after 5 regeneration cycles. Results of total organic carbon confirmed that paracetamol was fully degraded to CO₂ and water.

Determination of Diosmin in Pharmaceutical Products with Chemically Modified Voltammetric Sensors

In this paper, the electrochemical behavior of two types of sensors based on modified screen-printed electrodes (one screen-printed electrode based on carbon (SPCE) and another screen-printed electrode modified with Prussian Blue (PB/SPCE)) was studied with the aim of sensitive detection of diosmin, an active pharmaceutical compound from the class of flavonoids. The scan electron microscopy technique was used for the morphological characterization of PB/SPCE. The preliminary analysis assessed the electrochemical behavior of SPCE and PB/SPCE in KCl solution and in a double solution of potassium ferrocyanide-potassium chloride. It was shown that the active area of PB/SPCE is superior to the one of SPCE, the greater sensitivity being related with the presence of the electroactive modifier. Similarly, in the case of diosmin detection, the PB/SPCE sensor detect more sensitivity the diosmin due to the electrocatalytic effect of PB. From the study of the influence of reaction rate on the sensor's electrochemical response, it was shown that the detection process is controlled by the adsorption process, the degree of surface coverage with electroactive molecules being higher in the case of PB/SPCE. From the PB/SPCE calibration curve, it wasdetermined that it has high sensitivity and low detection and quantification limit values (limit of detection 5.22 × 10^-8 M). The applicability of the PB/SPCE sensor was confirmed by sensitive analysis of diosmin in pharmaceutical products. The voltammetric method is suitable for the detection and quantification of diosmin in pharmaceutical products. The method is simple, accurate, and quick and can be used in routine analysis in the examination of the quality of pharmaceutical products and other types of samples.

Comparison of Raman and attenuated total reflectance (ATR) infrared spectroscopy for water quantification in natural deep eutectic solvent

Natural deep eutectic solvents (NADES) are ionic solutions, of great interest for extraction from biomass, biocatalysis, and nanoparticle synthesis. They are easily synthesised and eco-friendly, have low volatility and high dissolution power, and are biodegradable. However, water content in NADES is a critical parameter, affecting their optimal use and extraction efficiency. Vibrational spectroscopic techniques are rapid, label-free, non-destructive, non-invasive, and cost-effective analytical tools that can probe the molecular composition of samples. A direct comparison between a previous study using attenuated total reflectance infrared (ATR-IR) spectroscopy for water quantification in NADES and the same investigation performed with Raman spectroscopy is presently reported. Three NADES systems, namely betaine-glycerol (BG), choline chloride-glycerol (CCG), and glucose-glycerol (GG), containing a range of water concentrations between 0% (w/w) and 40% (w/w), have been analysed with Raman spectroscopy coupled to partial least squares regression multivariate analysis. The values of root mean square error of cross-validation (RMSECV) obtained from analysis performed on the pre-processed spectra over the full spectral range (150-3750 cm^-1) are respectively 0.2966% (w/w), 0.4703% (w/w), and 0.2351% (w/w) for BG, GG, and CCG. While the direct comparison to previous ATR-IR results shows essentially similar outcomes for BG, the RMSECV is 33.14% lower and 65.84% lower for CG and CCG. Furthermore, mean relative errors obtained with Raman spectroscopy, and calculated from a set of samples used as independent samples, were 1.452% (w/w), 1.175% (w/w), and 1.188% (w/w). Ultimately, Raman spectroscopy delivered performances for quantification of water in NADES with similar accuracy to ATR-IR. The present demonstration clearly highlights the potential of Raman spectroscopy to support the development of new analytical protocols in the field of green chemistry.

Analytical Methods for Determination of Antiviral Drugs in Different Matrices: Recent Advances and Trends

Viruses are the main pathogenic substances that cause severe diseases in humans and other living things. They are among the most common microorganisms, and consequently, antiviral drugs have emerged to prevent and treat viral infections. Antiviral drugs are an essential drug group considering their prescription and consumption rates for different diseases and indications. Therefore, it is crucial to develop accurate and precise analytical methods to detect antiviral drugs in various matrices. Chromatographic techniques are used frequently for the quantification purpose since they allow simultaneous determination of antivirals. Electrochemical methods have also gained importance since the analysis can be performed quickly without the need for pretreatment. Spectrophotometric and spectrofluorimetric methods are used because they are simple, inexpensive, and less time-consuming methods. The purpose of this review is to present an overview of the analysis of currently used antiviral drugs from 2010 to 2021. Since studies on antiviral drugs are numerous, selected publications were reviewed in this article. The analysis of antiviral drugs was divided into three main groups: chromatographic, spectrometric, and electrochemical methods which were applied to different matrices, including pharmaceutical, biological, and environmental samples.

Quantification and Classification of Diclofenac Sodium Content in Dispersed Commercially Available Tablets by Attenuated Total Reflection Infrared Spectroscopy and Multivariate Data Analysis

A new methodology, based on Fourier transform infrared spectroscopy equipped with an attenuated total reflectance accessory (ATR FT-IR), was developed for the determination of diclofenac sodium (DS) in dispersed commercially available tablets using chemometric tools such as partial least squares (PLS) coupled with discriminant analysis (PLS-DA). The results of PLS-DA depicted a perfect classification of the tablets into three different groups based on their DS concentrations, while the developed model with PLS had a sufficiently low root mean square error (RMSE) for the prediction of the samples’ concentration (~5%) and therefore can be practically used for any tablet with an unknown concentration of DS. Comparison with ultraviolet/visible (UV/Vis) spectrophotometry as the reference method revealed no significant difference between the two methods. The proposed methodology exhibited satisfactory results in terms of both accuracy and precision while being rapid, simple and of low cost.

Overcoming the paracetamol dose challenge with wrinkled mesoporous carbon spheres

Paracetamol is the most commonly used antipyretic and analgesic drug in the world. The key challenge in paracetamol therapy is associated with the frequency of the dosing. Depending on the gastric filling within 10-20 min paracetamol is released and rapidly absorbed from the gastrointestinal tract. Therefore, it must be taken three or four times a day. To address the dose challenge it is desirable that the paracetamol release profile follows the zero-order kinetic model (constant rate of drug release per unit time). This goal can be achieved by using a suitable porous carrier system. Herein, non-toxic wrinkled mesoporous carbons with unique morphology were synthesized via the hard template method as new carriers for paracetamol. These particles can precisely modulate the release of paracetamol over 24 h in a simulated gastric fluid according to the zero-order kinetic model completely eliminating the initial burst release. Overall, these systems could significantly enhance the bioavailability of paracetamol and prolong its therapeutic effect in numerous diseases such as cold, flu, COVID-19, and severe pain.

Design of Paracetamol Delivery Systems Based on Functionalized Ordered Mesoporous Carbons

The oxidized ordered mesoporous carbons of cubic and hexagonal structure obtained by two templating methods (soft and hard) were applied for the first time as delivery systems for paracetamol—the most common antipyretic and analgesic drug in the world. The process of carbon oxidation was performed using an acidic ammonium persulfate solution at 60 °C for 6 h. The functionalization was found to reduce the specific surface area and pore volume of carbon materials, but it also led to an increasing number of acidic oxygen-containing functional groups. The most important element and the novelty of the presented study was the evaluation of adsorption and release ability of carbon carriers towards paracetamol. It was revealed that the sorption capacity and the drug release rate were mainly affected by the materials’ textural parameters and the total amount of surface functional groups, notably different in pristine and oxidized samples. The adsorption of paracetamol on the surface of ordered mesoporous carbons occurred according to different mechanisms: donor–acceptor complexes and hydrogen bond formation. The adsorption kinetics was assessed using pseudo-first- and pseudo-second-order models. The regression results indicated that the adsorption kinetics was more accurately represented by the pseudo-second-order model. Paracetamol was adsorbed onto the carbon materials studied following the Langmuir type isotherm. The presence of oxygen-containing functional groups on the surface of ordered mesoporous carbons enhanced the amount of paracetamol adsorbed and its release rate. The optimal drug loading capacity and expected release pattern exhibited oxidized ordered mesoporous carbon with a hexagonal structure obtained by the hard template method.

Sustainable environment-friendly quantitative determination of three anti-hyperlipidemic statin drugs and ezetimibe in binary mixtures by first derivative Fourier transform infrared (FTIR) spectroscopy

FTIR spectrometry is considered a sustainable green analytical chemistry procedure. Its use in quantitative analysis of pharmaceutical compounds in their raw resources and in their dosage forms is growing currently. The current research offers an environment-friendly, speedy, cost-effective, reliable and easy method for the simultaneous estimation of anti-hyperlipidemic drugs. No sample preparation was required except for grinding and mixing with KBr for making pellets used for acquisition of the FT-IR spectra. First-derivative FTIR spectroscopy is used to assess quantitatively atorvastatin (ATR), rosuvastatin (RSV) and simvastatin (SMV) in their binary mixtures with ezetimibe (EZT). For the first mixture, EZT and ATR were determined at 1733.18 cm^-1 and 1647.74 cm^-1, respectively. In the second mixture, the zero-crossing wave numbers selected for the determination of EZT and RSV were 1733.18 cm^-1 and 955.69 cm^-1, correspondingly. Whereas, the third mixture was quantified at the wavenumbers of 1520.93 and 3569.68 cm^-1 for EZT and SMV, respectively. Validation of the procedure has been performed complying with recommendations of the International Conference of Harmonization (ICH) presenting linearity, accuracy, precision, robustness and selectivity. The linear range for all drugs was 2-30 mg/g. It was found that the LOD was 0.607, 0.311, 0.491 and 0.395 mg/g and the LOQ was found to be 1.839, 0.942, 1.490 and 1.190 mg/g for EZT, ATR, RSV, and SMV, correspondingly. The proposed technique was found to be accurate and precise in terms of percentage error and percentage relative standard deviation among intraday and interday measurements. It was also found selective through comparison of the results of standard drugs with results of binary mixtures and of pharmaceutical tablets. It was found robust through making slight variations in the working conditions and the results obtained remained statistically equivalent. The technique was applied effectively for the estimation of the binary mixtures under study in their tablets. Comparing the found outcomes to those of reference derivative UV spectrophotometric methods gave no significant difference between them. Analytical eco-scale and the scale of Green Analytical Procedure Index (GAPI) are the two scales utilized for evaluation of the greenness of the technique and it was found to be excellent green.

A rapid FTIR spectroscopic assay for quantitative determination of Memantine hydrochloride and Amisulpride in human plasma and pharmaceutical formulations

A selective, new, rapid and nondestructive Fourier transform Infrared spectroscopic assay has been developed for simultaneous determination of Memantine hydrochloride and Amisulpride in human plasma and their pharmaceutical formulations without interference from common dugs excipients. A binary mixture of ME and nonselective β-blocker namely; carvidalol has been determined the solid-state by FTIR spectroscopy for the first time. The linear range had been extent from 1.0 to 8.0 and 1.0 to 10.0 μg/mg, for ME and AMS respectively. The detection limits were 0.29 and 0.23 μg/mg while quantitation limits were 0.90 and 0.71 μg/mg for ME and AMS respectively. The developed assay has been validated according to ICH & USP recommendations and successfully applied for quantitative determination of selected drugs in biological fluid.

Characterization, optimization and kinetics study of acetaminophen degradation by Bacillus drentensis strain S1 and waste water degradation analysis

Background

In this study, the biodegradation of N-acetyl-para-aminophenol also known as acetaminophen (APAP, paracetamol) was studied by bacterial strain Bacillus drentensis strain S1 (accession no. KY623719) isolated from sewage sample.

Results

The Bacillus drentensis strain S1 was isolated from the sewage sample using the enrichment culture method. As per our knowledge this is the first Bacillus drentensis strain reported for the degradation of APAP. In this study a 20-L batch reactor was employed for degradation of APAP. The maximum specific growth rate (μmax) was observed at 400 mg/L concentration of APAP. The pilot-scale anaerobic batch reactor of was stable and self-buffered. The degradation in pilot-scale reactor was slow as compared to batch experiments due to fluctuation in pH and exhaustion of nutrients. Design-Expert® software was used for optimization of conditions for APAP degradation; such as temperature (40 °C), pH (7.0), concentration of APAP (300 g/L) and agitation speed (165 rpm). The FTIR and GC–MS were used to identify the degradation metabolites. The intermediates of degradation like 2-isopropyl-5-methylcyclohexanone and phenothiazine were observed, based on these results the metabolic pathway has been predicted.

Conclusions

The optimization, kinetic, batch study and pilot study indicates the potential of Bacillus drentensis strain S1 for degradation of acetaminophen. The experimental design, optimization and statistical analysis were performed by Design Expert® software. The optimal growth condition for Bacillus drentensis strain S1 was found to be at temperature 40 °C, pH 7, acetaminophen at concentration of 300 (mg/L) and agitation speed 165 rpm. The GC–MS and FTIR was used for identification of metabolites produced during acetaminophen degradation and the partial metabolic pathway for degradation of acetaminophen was also proposed .

Quantitative analysis of cefazolin sodium in lyophilized powder by infrared spectrophotometry: Green, low cost, fast and effective

Cefazolin sodium is a broad-spectrum antibiotic used in the treatment of infectious diseases in humans and in the surgical prophylaxis. Thus, since a considerable number of people have access to this drug, it is of great interest of quality control. The aim of this study was development and validation of a green method by Fourier-Transform Infrared (FT-IR) transmission spectrophotometry for the quantification of cefazolin sodium in lyophilized powder. This technique is widely used in the pharmaceutical industry due to its ease of execution, low cost, safety and high precision and accuracy. It has been employed in the quality control routine of numerous pharmaceuticals in order to identify them and quantify their active principles. The proposed method was completely validated according ICH guidelines, showing selectivity, accuracy, precision, robustness and linearity. It was linear over the concentration range of 0.4-1.7 mg with correlation coefficient 0.999, limits of detection and quantification of 0.017 mg and 0.052 mg, respectively, precise, accurate and robust when changes in the time, pressure and mark of potassium bromide were carried out during the preparation of the pellets. The proposed method was successfully applied to the qualitative and quantitative quality control of cefazolin sodium in lyophilized powder. In addition, the method is considered green, clean and sustainable since it uses only a single reagent; it is a fast, low-cost and environmentally friendly method.

Evolution of green chemistry and its multidimensional impacts: A review

The growing process of industrialization was a milestone for world economic evolution. Since the 1940s, social movements have revolutionized green chemistry and provided shifts in industrial positions and sustainable processes with advances in environmental impact and awareness of companies and population. Paul Anastas and John Warner, in the 1990s, postulated the 12 principles of Green Chemistry, which are based on the minimization or non-use of toxic solvents in chemical processes and analyzes, as well as, the non-generation of residues from these processes. One of the most active areas of Research and Development in Green Chemistry is the development of analytical methodologies, giving rise to the so-called Green Analytical Chemistry. The impacts of green chemistry on pharmaceutical analyzes, environmental, population, analyst and company are described in this review and they are multidimensional. Every choice and analytical attitude has consequences both in the final product and in everything that surrounds it. The future of green chemistry as well as our future and the environment is also contemplated in this work.

FTIR Spectrophotometry as a Green Tool for Quantitative Analysis of Drugs: Practical Application to Amoxicillin

Amoxicillin is an antimicrobial agent that belongs to the penicillin compounds. Its bactericidal action causes a destruction of the cell wall of bacteria. It is widely used in clinical practice, and it belongs to the Brazilian National List of Essential Drugs (RENAME). In literature, there are some green analytical methods for the amoxicillin analysis; however, none of them is focused on its quantification in capsules. Therefore, the aim of this study was to validate an environmentally friendly analytical method for the analysis of this antimicrobial action in capsules, using spectrophotometry in the mid-infrared region. The analyses were performed in the spectral range of 1815–1736 cm−1, and the samples were analyzed as potassium bromide pellets. The method was validated according to the ICH guidelines and Brazilian legislation. Linearity, selectivity, precision, accuracy, and robustness were evaluated and showed adequate results for method validation, in a concentration range of 0.5–1.5 mg/pellet. Thus, it is concluded that the validated spectrophotometric method is able to quantify amoxicillin in capsules. In addition, it is a fast, economical, and environmentally friendly method, since it does not use organic solvents, and it can be used for quality control of routine analysis of this drug.

Quantitative screening of the pharmaceutical ingredient for the rapid identification of substandard and falsified medicines using reflectance infrared spectroscopy

The World Health Organization suggests that approximately 10% of medicines worldwide are either falsified or substandard with higher figures in low and middle income countries. Such poor quality medicines can seriously harm patients and pose a threat to the economy worldwide. This study investigates attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy as a simple and rapid method for determination of drug content in tablet dosage forms. Paracetamol was used as the model pharmaceutical ingredient. Spectra of standard mixtures of paracetamol with different excipients formed the basis for multivariate PLS based quantitative analysis of simulated tablet content using different selected infrared absorbance bands. Calibration methods using ATR-FTIR were compared with the ATR-FTIR and conventional ultraviolet spectroscopic analyses of real tablet samples and showed that the paracetamol/microcrystalline cellulose mixtures gave optimum results for all spectral bands tested. The quantitative data for band 1524-1493cm-1 was linear (R2 ˃ 0.98; LOQ ≥ 10%w/w tablet). Global examples of paracetamol tablets were tested using this protocol and 12% of the tablet samples examined was identified as substandard. Each sample analysis was completed in just a few minutes. ATR-FTIR can therefore be used in the rapid screening of tablet formulations. The simplicity of the proposed method makes it appropriate for use in low and middle income countries where analytical facilities are not available.

A new analytical device incorporating a nitrogen doped lanthanum metal oxide with reduced graphene oxide sheets for paracetamol sensing

The novel N-CeO₂ nanoparticles decorated on reduced graphene oxide (N-CeO₂@rGO) composite has been synthesized by sonochemical method. The characterization of as prepared nanocomposite was intensely performed by UV-Vis, FT-IR, EDX, FE-SEM, HR-TEM, XRD, and TGA analysis. The synthesized nanomaterial was further investigated for its selective and sensitive sensing of paracetamol (PM) based on a N-CeO₂@rGO modified glassy carbon electrode. A distinct and improved reversible redox peak of PM is obtained at N-CeO₂@rGO nanocomposite compared to the electrodes modified with N-CeO₂ and rGO. It displays a very good performance with a wide linear range of 0.05-0.600 μM, a very low detection limit of 0.0098 μM (S/N = 3), a high sensitivity of 268 μA µM^-1 cm^-2 and short response time (<3 s). Also, the fabricated sensor shows a good sensibleness for the detection of PM in various tablet samples.

A rapid Fourier transform infrared spectroscopic method for analysis of certain proton pump inhibitors in binary and ternary mixtures

A simple and non-destructive FTIR method was used to determine certain proton pump inhibitors (PPIs) in binary and ternary mixtures. Proton pump inhibitors (PPIs); omeprazole (OMZ), esomeprazole (EZM), lansoprazole (LAN), pantoprazole sodium (PAN sodium) and rabeprazole sodium (RAB sodium) in binary mixture with domperidone (DOM) and ternary mixture of OMZ, clarithromycin (CLM) and tinidazole (TNZ) were determined in the solid-state by FTIR spectroscopy for the first time. The method was validated according to ICH-guidelines where linearity was ranged from 20 to 850μg/g and 20-360μg/g for PPIs and DOM, respectively in binary mixtures and 10-400, 100-8000 and 150-14,000μg/g for OMZ, CLM and TNZ, respectively. Limits of detection were found to be 6-100 and 9-100μg/g for PPIs and DOM, respectively and 4, 40 and 50μg/g for OMZ, CLM and TNZ, respectively. The method was applied successfully for determination of the cited drugs in their respective pharmaceutical dosage forms.