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1.
J AOAC Int ; 107(1): 146-157, 2024 Jan 04.
Article in English | MEDLINE | ID: mdl-37494481

ABSTRACT

BACKGROUND: Drug impurities are now seen as a major threat to the production of pharmaceuticals around the world and a major part of the global contamination problem, especially when it comes to carcinogenic impurities. OBJECTIVE: We present the first spectrophotometric strategy based on a combination of univariate and multivariate methods as impurity profiling methods for the estimation of lignocaine (LIG) and fluorescein (FLS) with their carcinogenic impurities: 2,6-xylidine (XYL) and benzene-1,3-diol (BZD). METHOD: The data processing strategy depends on overcoming unresolved bands by employing five affordable, accurate, selective, and sensitive methods. The methods applied were a direct UV univariate spectrophotometric analysis (D0) and four multivariate chemometric methods, including classical least squares (CLS), principal component regression (PCR), partial least squares (PLS), and genetic algorithm (GA-PLS). FLS analysis (1-16 µg/mL) was performed using the D0 method at 478 nm; then, the application of the ratio subtraction method (RSM) allowed the removal of interference caused by the FLS spectrum. From the resulting ratio spectra, LIG, XYL, and BZD can be efficiently determined by chemometrics. The calibration set was carefully selected at five concentration levels using a partial factorial training design, resulting in 25 mixtures with central levels of 160, 40, and 3 µg/mL for LIG, XYL, and BZD, respectively. Another 13 samples were applied to validate the predictive ability. RESULTS: The statistical parameters demonstrated exceptional recoveries and smaller prediction errors, confirming the experimental model's predictive power. CONCLUSIONS: The proposed approach was effectively tested using newly FDA-approved LIG and FLS pharmaceutical preparation and aqueous humor. Additionally, it was effectively assessed for whiteness, greenness, and sustainability using five assessment tools. HIGHLIGHTS: With its remarkable analytical performance, sustainability, affordability, simplicity, and cost-efficiency, the proposed strategy is an indispensable tool for quality control and in situ analysis in little-equipped laboratories, increasing the proposed approach's surveillance ability.


Subject(s)
Chemometrics , Neoplasms , Humans , Aqueous Humor , Spectrophotometry/methods , Least-Squares Analysis , Calibration
2.
Waste Manag ; 174: 362-370, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38101232

ABSTRACT

Large amounts of titanium white waste are generated in the production of titanium dioxide using sulphate method, which in turn can be used to prepare LiFePO4 cathode material, thereby reducing environmental risks and achieving resource recovery. However, a key challenge lies in the elimination of impurities. In this work, a cost-efficient and straightforward approach based on phase transformation during hydrothermal treatment was proposed to utilize titanium white waste with calcium dihydrogen phosphate for the preparation of LiFePO4 cathode material. The content of Fe in the leachate was enriched to 81.5 g/L after purification, while 99.9 % of Ti and 98.36 % of Al and were successfully removed. In the subsequent process for Fe/P mother liquor preparation, the losses of Fe and P were only 5.82 % and 2.81 %, respectively. The Fe and P contents of the synthesized FePO4 product were 29.47 % and 17.08 %, respectively, and the Fe/P molar ratio was 0.986. Crystal phase of the product matched well with standard iron phosphate, and the lamellar microstructure of FePO4 was uniform with the particle size ranging from 3 to 5 µm. Moreover, the contents of impurities in the product were far below the standard. The initial discharge of LiFePO4 synthesized by the iron phosphate was 160.6 mAh.g-1 at 0.1C and maintained good reversible capacity after 100 cycles. This work may provide new strategy for preparing LiFePO4 cathode material from industrial solid waste.


Subject(s)
Calcium Phosphates , Ferric Compounds , Iron , Lithium , Titanium , Iron/chemistry , Lithium/chemistry , Calcium , Phosphates/chemistry , Electrodes
3.
BMC Chem ; 17(1): 163, 2023 Nov 24.
Article in English | MEDLINE | ID: mdl-37996961

ABSTRACT

Two simple and rapid chromatographic methods were developed and validated for the analysis of levamisole and triclabendazole simultaneously in pure and pharmaceutical products. The first method is thin-layer chromatography (TLC) with densitometry, and the second method is high-performance liquid chromatography with PDA detection (HPLC-PDA). A Hypersil BDS C18 column with dimensions of 4.6 × 150 mm and a particle size of 5 µm was used in the HPLC-PDA method. An isocratic condition was used to carry out the separation, and the mobile phase was made up of acetonitrile and a 0.03 M potassium dihydrogen phosphate buffer in double-distilled water. The ratio of the mobile phase preparation was 70:30 (v/v), and the flow rate was 1 mL/min. A wavelength of 215 nm was employed for analyte detection. Precoated silica gel 60 F254 aluminium plates were used for the TLC method's separation. Mobile phase was made of ethyl acetate, hexane, methanol, and ammonia (69:15:15:1) for the separation. The detection wavelength selected was 215 nm. According to the International Council for Harmonization (ICH) guidelines, the proposed methods were validated and it was found that the two chromatographic methods are accurate, precise, and linear for both compounds in the range of 3.75-37.5 and 6-60 mg/L for the HPLC method for levamisole and triclabendazole, respectively and in the range of 2-14 µg/spot for the TLC method. The developed methods greenness profile was assessed using AGREE and ComplexGAPI tools.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 302: 123161, 2023 Dec 05.
Article in English | MEDLINE | ID: mdl-37478754

ABSTRACT

A novel diffuse reflectance fourier transform infrared spectroscopic method accompanied by chemometrics was optimized to fulfill the white analytical chemistry and green analytical chemistry principles for the quantification of cinnarizine and piracetam for the first time without any prior separation in their challenging pharmaceutical preparation, which has a pretty substantial difference in the concentration of cinnarizine/piracetam (1:16). Furthermore, the suggested method was used for cinnarizine/piracetam dissolution testing as an effective alternative to traditional methods. For the cinnarizine/piracetam dissolution tests, we used a dissolution vessel with 900 mL of phosphate buffer pH 2.5 at 37 °C ± 0.5 °C, then the sampling was carried out by frequent withdrawal of 20 µl samples from the dissolution vessel at a one-minute interval, over one hour, then representative fourier transform infrared spectra were recorded. To create a partial-least-squares regression model, a fractional factorial design with 5 different levels and 2 factors was used. This led to the creation of 25 mixtures, 15 as a calibration set and 10 as a validation set, with varying concentration ranges: 1-75 and 16-1000 µg/mL for cinnarizine/piracetam, respectively. Upon optimization of the partial-least-squares regression model, in terms of latent variables and spectral region, root mean square error of cross-validation of 0.477 and 0.270, for cinnarizine/piracetam respectively, were obtained. The optimized partial-least-squares regression model was further validated, providing good results in terms of recovery% (around 98 to 102 %), root mean square error of prediction (0.436 and 3.329), relative root mean square error of prediction (1.210 and 1.245), bias-corrected mean square error of prediction (0.059 and 0.081), and limit of detection (0.125 and 2.786) for cinnarizine/piracetam respectively. Ultimately, the developed method was assessed for whiteness, greenness, and sustainability using five assessment tools. the developed method achieved a greener national environmental method index and complementary green analytical procedure index quadrants with higher eco-scale assessment scores (91), analytical greenness metric scores (0.87), and red-greenblue 12 algorithm scores (89.7) than the reported methods, showing high practical and environmental acceptance for quality control of cinnarizine/piracetam.


Subject(s)
Cinnarizine , Piracetam , Spectroscopy, Fourier Transform Infrared/methods , Cinnarizine/analysis , Chemometrics , Quality Control , Least-Squares Analysis
5.
Food Chem ; 426: 136579, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37352707

ABSTRACT

Nowadays, veterinary medicine residues have been viewed as a major threat to food safety worldwide, especially when dealing with carcinogenic residues. Herein, we present the first differential pulse voltammetric method for the quantification of lignocaine and its carcinogenic metabolite 2,6-xylidine residues in bovine food samples, aided by five greenness and whiteness assessment tools, including NEMI, ESA, ComplexGAPI, AGREE, and RGB12. The method depends on the electrochemical oxidation after modification of the carbon paste sensor with recycled Al2O3-NPs functionalized multi-walled carbon nanoparticles. The produced sensor (Al2O3-NPs/MWCNTs/CPE) was characterized using XRD, FT-IR, EDX, SEM, and TEM. As expected, the active surface area and electron transfer processes were accelerated by the modification, resulting in ultra-sensitive quantification with detection limits of 19.00 and 13.94 nM for lignocaine and 2,6-xylidine, respectively. In terms of greenness, whiteness, sustainability, analytical effectiveness, and economic and practical considerations, the proposed method outperforms the reported methods.


Subject(s)
Carcinogens , Nanoparticles , Animals , Cattle , Carbon/chemistry , Lidocaine , Spectroscopy, Fourier Transform Infrared , Electrodes , Electrochemical Techniques/methods , Nanoparticles/chemistry
6.
Gels ; 9(2)2023 Feb 11.
Article in English | MEDLINE | ID: mdl-36826322

ABSTRACT

Although Cs(I) and Sr(II) are not strategic and hazardous metal ions, their recovery from aqueous solutions is of great concern for the nuclear industry. The objective of this work consists of designing a new sorbent for the simultaneous recovery of these metals with selectivity against other metals. The strategy is based on the functionalization of algal/polyethyleneimine hydrogel beads by phosphonation. The materials are characterized by textural, thermo-degradation, FTIR, elemental, titration, and SEM-EDX analyses to confirm the chemical modification. To evaluate the validity of this modification, the sorption of Cs(I) and Sr(II) is compared with pristine support under different operating conditions: the pH effect, kinetics, and isotherms are investigated in mono-component and binary solutions, before investigating the selectivity (against competitor metals) and the possibility to reuse the sorbent. The functionalized sorbent shows a preference for Sr(II), enhanced sorption capacities, a higher stability at recycling, and greater selectivity against alkali, alkaline-earth, and heavy metal ions. Finally, the sorption properties are compared for Cs(I) and Sr(II) removal in a complex solution (seawater sample). The combination of these results confirms the superiority of phosphonated sorbent over pristine support with promising performances to be further evaluated with effluents containing radionuclides.

7.
Spectrochim Acta A Mol Biomol Spectrosc ; 287(Pt 2): 122114, 2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36399967

ABSTRACT

Atorvastatin and bisoprolol are two medications often prescribed together for the management of cardiovascular disease and to reduce mortality. Through a simple and direct technique based on deconvolution and synchronous of the spectrofluorometric spectra, the innovative method enables simultaneous quantification of bisoprolol and atorvastatin as single or co-formulated dosage forms in bulk and plasma. The method depends on measuring the amplitudes of bisoprolol and atorvastatin at 298 nm and 363 nm directly after deconvolution where the other drug doesn't show interference. The linearity of the method was 0.02-0.5 µg/mL and 0.3-25 µg/mL for bisoprolol and atorvastatin, respectively. LOD and LOQ were 0.004, 0.085 µg/mL and 0.013, 0.259 µg/mL for bisoprolol and atorvastatin respectively. Furthermore, green assessment of the method using Eco-Scale and GAPI scale. The method was precise, economical, simple, smart, time-saving and eco-friendly, which allowed its application in quality control unit and in lab assessment.


Subject(s)
Bisoprolol , Plasma , Atorvastatin , Spectrometry, Fluorescence , Quality Control
8.
RSC Adv ; 12(30): 19133-19143, 2022 Jun 29.
Article in English | MEDLINE | ID: mdl-35865580

ABSTRACT

A new sensor for alogliptin benzoate (ALG) estimation based on a simple and sensitive method was evolved on multiwalled-carbon-nanotube modified nanocrystalline zinc chromite carbon paste electrodes (ZnCr2O4@MWCNTs/CPEs). ALG electrochemical behavior was evaluated using a cyclic voltammetry (CV), square wave voltammetry (SWV) and chronoamperometry (CA). The new electrode materials were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray analysis (EDX) for elemental analysis and mapping, and X-ray diffraction (XRD) and the X-ray photoelectron spectroscopy (XPS) measurements. All these measurements exhibiting enhanced activity and high conductivity compared to the bare electrode without modification. The calibration curves obtained for ALG were in the ranges of 0.1-20 µmol L-1 with a quantification and detection limits of 0.09 and 0.03 µmol L-1, respectively. The prepared sensor showed a good sensitivity and selectivity with less over potential for ALG determination. Finally, the presented method was successfully applied as a simple, precise and selective electrochemical electrode for the estimation of ALG in its pharmaceutical dosage form.

9.
J AOAC Int ; 105(6): 1755-1761, 2022 Oct 26.
Article in English | MEDLINE | ID: mdl-35758559

ABSTRACT

BACKGROUND: Tamsulosin (TAM) and dutasteride (DUT) are ranked among the most frequently prescribed therapies in urology. Interestingly, studies have also been carried out on TAM/DUT in terms of their ability to protect against recent COVID-19. However, very few studies were reported for their simultaneous quantification in their combined dosage form and were mainly based on chromatographic analysis. Subsequently, it is very important to offer a simple, selective, sensitive, and rapid method for the quantification of TAM and DUT in their challenging dosage form. OBJECTIVE: In this study, a new chemometrically assisted ultraviolet (UV) spectrophotometric method has been presented for the quantification of TAM and DUT without any prior separation. METHOD: For the calibration set, a partial factorial experimental design was used, resulting in 25 mixtures with central levels of 20 and 25 µg/mL for TAM and DUT, respectively. In addition, to assess the predictive ability of the developed approaches, another central composite design of 13 samples was used as a validation set. Post-processing by chemometric analysis of the recorded zero-order UV spectra of these sets has been applied. These chemometric approaches include partial least-squares (PLS) and genetic algorithm (GA), as an effective variable selection technique, coupled with PLS. RESULTS: The models' validation criteria displayed excellent recoveries and lower errors of prediction. CONCLUSIONS: The proposed models were effectively used to determine TAM/DUT in their combined dosage form, and statistical comparison with the reported method revealed satisfactory results. HIGHLIGHTS: Overall, this work presents powerful simple, selective, sensitive, and precise methods for simultaneous quantification of TAM/DUT in their dosage form with satisfactory results. The predictive ability and accuracy of the developed methods offer the opportunity to be employed as a quality control technique for the routine analysis of TAM/DUT when chromatographic instruments are not available.


Subject(s)
COVID-19 , Research Design , Humans , Dutasteride , Tamsulosin , Spectrophotometry, Ultraviolet/methods , Least-Squares Analysis , Calibration , Pharmaceutical Preparations , Spectrophotometry
10.
RSC Adv ; 12(27): 17536-17549, 2022 Jun 07.
Article in English | MEDLINE | ID: mdl-35765456

ABSTRACT

A simple, cheap, sensitive, and time-saving square wave voltammetric (SWV) procedure using a carbon paste electrode modified with aluminum oxide nanoparticle decorated multi-walled carbon nanoparticles (Al2O3-NPs/MWCNTs/CPE) is presented for the ultra-sensitive determination of tamsulosin (TAM) and solifenacin (SOL), one of the most prescribed pharmaceutical combinations in urology. Characterization of the developed electrode was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD) patterns, energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM) and FT-IR spectrophotometry. The voltammetric behavior of TAM/SOL was evaluated using Al2O3-NPs in different content and electrode compositions. The use of Al2O3 functionalized MWCNTs as a CPE modifier increased the process of electron transfer as well as improved the electrode active surface area therefore, ultra-sensitive results were acquired with a linear range of 10-100 and 12-125 ng ml-1 for TAM and SOL respectively, and a limit of the detection value of 2.69 and 3.25 ng ml-1 for TAM and SOL, respectively. Interestingly, the proposed method succeeded in quantifying TAM and SOL with acceptable percentage recoveries in dosage forms having diverged concentration ranges and in the biological fluids with very low peak plasma concentration (C max). Furthermore, the proposed method was validated, according to the ICH criteria, and shown to be accurate and reproducible.

11.
Eur Rev Med Pharmacol Sci ; 26(7): 2579-2585, 2022 04.
Article in English | MEDLINE | ID: mdl-35442473

ABSTRACT

OBJECTIVE: The aim of the study was to detect the effect of COVID-19 on lymphocyte and platelet parameters among Sudanese patients admitted to Intensive Care unit (ICU) and emergency (ER). PATIENTS AND METHODS: This cross-sectional study was carried out on a total of 787 Sudanese individuals (487 confirmed COVID-19 cases and 300 apparently healthy individuals as controls, in duration between April 2020 to December 2020). Platelets (PLTs) and platelet indices, mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT) and platelet larger cell ratio (PLCR) were investigated as part of the complete blood count (CBC) for the case and control group. Also, the neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR) were calculated, and the results were statistically analyzed by SPSS version 21. RESULTS: The severity of the disease was also affected by the patient's age: 262 COVID-19 cases admitted to ICU were over 50 years old, compared to only four patients in the mild group. Regarding hematological parameters, the absolute lymphocyte count, PLTs, MPV, PDW, and P-LCR were significantly different between cases and control groups (p-values = 0.000, 0.002, 0.000, 0.000, and 0.000, respectively). PLR and NLR levels were found to be significantly higher as disease severity increased; p-values = 0.000 and 0.000, respectively. The study also demonstrated that lymphopenia was associated with severe COVID-19 infection (in 93% of ICU patients, 59.9% of ER, and 9% of the mild group), while thrombocytopenia was detected only among 30.8% of ICU patients. CONCLUSIONS: Lymphopenia and thrombocytopenia are associated with severe COVID-19 infection. NLR and PLR were markedly increased with COVID-19.


Subject(s)
COVID-19 , Lymphopenia , Thrombocytopenia , Blood Platelets , Cross-Sectional Studies , Humans , Intensive Care Units , Lymphocytes , Mean Platelet Volume , Middle Aged , Neutrophils , Platelet Count , Retrospective Studies , Thrombocytopenia/epidemiology
12.
Polymers (Basel) ; 13(9)2021 May 08.
Article in English | MEDLINE | ID: mdl-34066682

ABSTRACT

High-tech applications require increasing amounts of rare earth elements (REE). Their recovery from low-grade minerals and their recycling from secondary sources (as waste materials) are of critical importance. There is increasing attention paid to the development of new sorbents for REE recovery from dilute solutions. A new generation of composite sorbents based on brown algal biomass (alginate) and polyethylenimine (PEI) was recently developed (ALPEI hydrogel beads). The phosphorylation of the beads strongly improves the affinity of the sorbents for REEs (such as La and Tb): by 4.5 to 6.9 times compared with raw beads. The synthesis procedure (epicholorhydrin-activation, phosphorylation and de-esterification) is investigated by XPS and FTIR for characterizing the grafting route but also for interpreting the binding mechanism (contribution of N-bearing from PEI, O-bearing from alginate and P-bearing groups). Metal ions can be readily eluted using an acidic calcium chloride solution, which regenerates the sorbent: the FTIR spectra are hardly changed after five successive cycles of sorption and desorption. The materials are also characterized by elemental, textural and thermogravimetric analyses. The phosphorylation of ALPEI beads by this new method opens promising perspectives for the recovery of these strategic metals from mild acid solutions (i.e., pH ~ 4).

13.
Molecules ; 26(4)2021 Feb 17.
Article in English | MEDLINE | ID: mdl-33671351

ABSTRACT

The strong demand for rare-earth elements (REEs) is driven by their wide use in high-tech devices. New processes have to be developed for valorizing low-grade ores or alternative metal sources (such as wastes and spent materials). The present work contributed to the development of new sorbents for the recovery of rare earth ions from aqueous solutions. Functionalized mesoporous silica composite was synthesized by grafting diethylenetriamine onto composite support. The physical and chemical properties of the new sorbent are characterized using BET, TGA, elemental analysis, titration, FTIR, and XPS spectroscopies to identify the reactive groups (amine groups: 3.25 mmol N g-1 and 3.41 by EA and titration, respectively) and their mode of interaction with Nd(III) and Gd(III). The sorption capacity at the optimum pH (i.e., 4) reaches 0.9 mmol Nd g-1 and 1 mmol Gd g-1. Uptake kinetics are modeled by the pseudo-first-order rate equation (equilibrium time: 30-40 min). At pH close to 4-5, the sorbent shows high selectivity for rare-earth elements against alkali-earth elements. This selectivity is confirmed by the efficient recovery of REEs from acidic leachates of gibbsite ore. After elution (using 0.5 M HCl solutions), selective precipitation (using oxalate solutions), and calcination, pure rare earth oxides were obtained. The sorbent shows promising perspective due to its high and fast sorption properties for REEs, good recycling, and high selectivity.


Subject(s)
Amines/chemistry , Gadolinium/chemistry , Neodymium/chemistry , Polymers/chemistry , Silicon Dioxide/chemistry , Adsorption , Hydrogen-Ion Concentration , Industrial Waste/analysis , Kinetics , Photoelectron Spectroscopy , Porosity , Solutions , Spectroscopy, Fourier Transform Infrared
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 251: 119465, 2021 Apr 15.
Article in English | MEDLINE | ID: mdl-33503564

ABSTRACT

Two chemometric assisted spectrophotometric models were applied for the quantitative analysis of velpatasvir and sofosbuvir in their newly FDA approved pharmaceutical dosage form. The UV absorption spectra of velpatasvir and sofosbuvir showed certain degree of overlap which exhibited degree of difficulty for the choice of certain method provides simultaneous quantitative analysis of the cited drugs. Artificial neural networks and genetic algorithm artificial neural networks were the suitable model for the quantitative analysis of velpatasvir and sofosbuvir in their binary mixture. Experimental design and building the calibration set for the binary mixture were achieved to implement the described models. The proposed models were optimized with the aid of five-levels, two factors experimental design. Spectral region of 380-400 nm was rejected which resulted in 181 variables. GA reduced absorbance matrix to 72 and 36 variables for velpatasvir and sofosbuvir respectively. The models succeeded to estimate the studied drugs with acceptable values of root mean square error of calibration and root mean square error of prediction. The developed models were successfully applied to the quantitative analysis of the two drugs in Epclusa® tablets. The results were statistically compared with another published quantitative analytical method with no significant difference by applying Student t-test and variance ratio F-test.


Subject(s)
Neural Networks, Computer , Sofosbuvir , Antiviral Agents , Carbamates , Heterocyclic Compounds, 4 or More Rings , Humans , Spectrophotometry , Tablets
15.
RSC Adv ; 11(7): 3834-3842, 2021 Jan 19.
Article in English | MEDLINE | ID: mdl-35424359

ABSTRACT

In this work, the quantitative determination of an erectile dysfunctional drug avanafil in the presence of its acid-induced degradation product was achieved via the application of a pre-optimized novel spectrofluorimetric method. The fluorescence emission wavelength was recorded at 370 and 407 nm, after being excited at 268 and 271 nm for avanafil and its acid-induced degradation product, respectively. Direct determination of avanafil based on its native fluorescence is restricted because the emission spectra of both components are heavily overlapped. Therefore, to overcome this constraint, a novel second derivative synchronous fluorescence method was evolved to eliminate this overlapping. The ideal determination wavelength was found to be 377 nm. Augmentation of lean six sigma (LSS) with response surface methodology (RSM) play a significant role in the development of robust specifications to ensure quality at the six sigma level with a high level of statistical confidence and targeted performance. All of the experimental conditions were optimized using D-optimal design as a RSM to select the optimal parameters. In addition, this work includes a graphical representation of the relationships between various variables that can greatly affect the results and the intensity of the synchronous fluorescence.

16.
Spectrochim Acta A Mol Biomol Spectrosc ; 244: 118871, 2021 Jan 05.
Article in English | MEDLINE | ID: mdl-32889340

ABSTRACT

Lesinurad and allopurinol combination is newly FDA approved for treatment of patients suffering from hyperuricemia associated with uncontrolled gout. In the present work, two different highly sensitive, selective and accurate fluorescence spectroscopic methods were developed for quantitative analysis of lesinurad and allopurinol in their pharmaceutical dosage form without any tedious operation procedure. Lesinurad was quantitatively analyzed based on its unique native fluorescence nature. Lesinurad fluorescence emission was quantitatively determined at 343 nm after excitation at 288 nm without any interference from allopurinol. Allopurinol, has free terminal secondary amino group, reacted with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBDCl) through nucleophilic substitution mechanism forming highly fluorescent dark yellow fluorophore. Allopurinol was quantitavely analyzed based on measurement the emission fluorescence intensity of the fluorescent dark yellow fluorophore at 535 nm after excitation at 465 nm. Different parameters which affect the described methods of the studied drugs were carefully checked and optimized. Calibration graphs were found to be linear over the concentration range of 0.25-4.0 µg/mL for lesinurad and 0.2-20 µg/mL for allopurinol. The proposed methods were successfully applied for the quantitative analysis of the two drugs in Duzallo® pharmaceutical dosage form and spiked human plasma.


Subject(s)
Allopurinol , Triazoles , Calibration , Humans , Spectrometry, Fluorescence , Thioglycolates
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 248: 119157, 2021 Mar 05.
Article in English | MEDLINE | ID: mdl-33218874

ABSTRACT

In the present study, a sensitive, selective and accurate synchronous fluorescence spectroscopic method was utilized for simultaneous estimation of elbasvir and grazoprevir in their pharmaceutical formulation. The developed method based on measurement of the synchronous fluorescence intensity of the studied drugs at constant wavelength difference (Δλ) = 50 nm. Elbasvir can be determined directly at 312 nm without interference from grazoprevir. Grazoprevir can be determined by application of dual wavelength method by taking the difference in synchronous fluorescence intensity at 390 & 372 nm to remove interference from elbasvir. Calibration graphs were found to be linear over the concentration range of 50-700 ng/mL for elbasvir and 100-900 ng/mL for grazoprevir. The developed method was successfully applied to the quantitative analysis of the two drugs in Zepatier® tablets.


Subject(s)
Antiviral Agents , Amides , Benzofurans , Carbamates , Cyclopropanes , Drug Compounding , Imidazoles , Quinoxalines , Spectrometry, Fluorescence , Sulfonamides , Tablets
18.
Andrologia ; 52(11): e13793, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32833250

ABSTRACT

Sexual dysfunction is more prevalent in psychotic patients than in the nonpsychotic population. The objective of this study was to identify correlations between serum prolactin levels, testosterone levels and erectile dysfunction in patients with first-episode psychosis (n = 40) compared to age-matched healthy controls (n = 40). All subjects underwent clinical evaluation, international index of erectile function (IIEF5) score assessment and measurement of serum prolactin and total testosterone levels. In first-episode psychotic patients, the IIEF-5 score and total testosterone levels were significantly lower, while serum prolactin levels were higher. We concluded that men with first-episode psychosis are at an increased risk for development of erectile dysfunction, and increased duration of untreated psychosis leads to a higher incidence of erectile dysfunction and hyperprolactinemia.


Subject(s)
Erectile Dysfunction , Hyperprolactinemia , Psychotic Disorders , Sexual Dysfunction, Physiological , Erectile Dysfunction/epidemiology , Erectile Dysfunction/etiology , Humans , Hyperprolactinemia/complications , Hyperprolactinemia/epidemiology , Male , Psychotic Disorders/complications , Psychotic Disorders/epidemiology , Testosterone
19.
Sci Total Environ ; 719: 137396, 2020 Jun 01.
Article in English | MEDLINE | ID: mdl-32143096

ABSTRACT

Composite beads (APEI*), obtained by the controlled interaction of algal biomass with PEI, followed by ionotropic gelation and crosslinking processes using CaCl2/glutaraldehyde solution, constitute efficient supports for metal binding. The quaternization of algal/PEI beads (Q-APEI*) significantly increases the sorption properties of the composite beads (APEI*) for As(V). The materials are characterized by SEM/EDX, TGA, BET, elemental analysis, FTIR, XPS, and titration. The sorption of As(V) is studied in function of pH while sorption mechanism is discussed in function of metal speciation and surface characteristics of the sorbent. Optimum sorption occurs at pH close to 7. Fast uptake kinetics, correlated to textural properties are successfully fitted by pseudo-first order rate equation and the Crank equation (for resistance to intraparticle diffusion); equilibrium is reached with 45-60 min. The Langmuir equation finely fits sorption isotherms; maximum sorption capacity reaches 1.34 mmol As g-1. Arsenic can be completely eluted using 0.5 M CaCl2/0.5 M HCl solutions; the sorbent maintains high sorption and desorption efficiencies for a minimum of 5 cycles. The sorbent is tested for the removal of As(V) from mining effluents containing high concentration of iron and traces of zinc. At pH 3, the sorbent shows remarkable selectivity for As(V) over Fe. After controlling the initial pH to 5, a sorbent dosage of 2 g L-1 is sufficient for achieving the complete recovery of As(V) from mining effluent (corresponding to initial concentration of 1.295 mmol As L-1).


Subject(s)
Polyethyleneimine/chemistry , Adsorption , Arsenic , Hydrogen-Ion Concentration , Kinetics , Solutions , Stramenopiles , Water , Water Pollutants, Chemical
20.
Molecules ; 24(21)2019 Oct 29.
Article in English | MEDLINE | ID: mdl-31671819

ABSTRACT

There is a need for developing new sorbents that incorporate renewable resources for the treatment of metal-containing solutions. Algal-polyethyleneimine beads (APEI) (reinforced with alginate) are functionalized by grafting amidoxime groups (AO-APEI). Physicochemical characteristics of the new material are characterized using FTIR, XPS, TGA, SEM, SEM-EDX, and BET. AO-APEI beads are tested for the recovery of Sr(II) from synthetic solutions after pH optimization (≈ pH 6). Uptake kinetics is fast (equilibrium ≈ 60-90 min). Sorption isotherm (fitted by the Langmuir equation) shows remarkable sorption capacity (≈ 189 mg Sr g-1). Sr(II) is desorbed using 0.2 M HCl/0.5 M CaCl2 solution; sorbent recycling over five cycles shows high stability in terms of sorption/desorption performances. The presence of competitor cations is studied in relation to the pH; the selectivity for Sr(II) is correlated to the softness parameter. Finally, the recovery of Sr(II) is carried out in complex solutions (seawater samples): AO-APEI is remarkably selective over highly concentrated metal cations such as Na(I), K(I), Mg(II), and Ca(II), with weaker selectivity over B(I) and As(V). AO-APEI appears to be a promising material for selective recovery of strontium from complex solutions (including seawater).


Subject(s)
Microspheres , Oximes/chemistry , Polyethyleneimine/chemistry , Rhodophyta/chemistry , Strontium/isolation & purification , Adsorption , Hydrogen-Ion Concentration , Kinetics , Photoelectron Spectroscopy , Rheology , Seawater/chemistry , Solutions , Temperature , Water Pollutants, Chemical/isolation & purification
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