Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Pharmaceuticals (Basel) ; 17(4)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38675464

RESUMEN

In the present work, an efficient isocratic HPLC method was developed for the precise and accurate estimation of vitamin D3 in tablet form. The chromatographic conditions comprised an L3 silica column (5 µm in particle size, 4.6 mm × 250 mm) with a mobile phase n-hexane/ethyl acetate (85:15 v/v) with a flow rate of 2.0 mL/min and a detection wavelength of 292 nm. The new methodology was validated for accuracy, precision, specificity, robustness, and quantification limits according to an official monograph of USP/BP and ICH guidelines. The peak areas of the six replicates of the homogeneous sample were recorded. The mean value obtained was 67,301, and the relative standard deviation (RSD) was 0.1741. The linearity and range were in the acceptable bounds, i.e., 0.999, which was calculated using regression line analysis. The results show that the method is truly acceptable as the RSD, as the flow rate was 0.81%, while for the mobile phase composition, it was 0.72%, which lies in the acceptable range. The limit of detection (LOD) and the limit of quantification (LOQ) values were 0.0539 µg/mL and 0.1633 µg/mL, respectively. The % RSD of the intra and inter-day precision of the method was deemed acceptable according to the international commission for harmonization guidelines. The developed method has potential to be used for the detection and quantification of vitamin D3 during routine analysis for tablets in dosage form.

2.
Nanoscale Adv ; 5(18): 4735-4751, 2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37705774

RESUMEN

The implementation of battery-like electrode materials with complicated hollow structures, large surface areas, and excellent redox properties is an attractive strategy to improve the performance of hybrid supercapacitors. The efficiency of a supercapattery is determined by its energy density, rate capabilities, and electrode reliability. In this study, a magnesium copper phosphate nanocomposite (MgCuPO4) was synthesized using a hydrothermal technique, and silver phosphate (Ag3PO4) was decorated on its surface using a sonochemical technique. Morphological analyses demonstrated that Ag3PO4 was closely bound to the surface of amorphous MgCuPO4. The MgCuPO4 nanocomposite electrode showed a 1138 C g-1 capacity at 2 A g-1 with considerably improved capacity retention of 59% at 3.2 A g-1. The increased capacity retention was due to the fast movement of electrons and the presence of an excess of active sites for the diffusion of ions from the porous Ag3PO4 surface. The MgCuPO4-Ag3PO4//AC supercapattery showed 49.4 W h kg-1 energy density at 550 W kg-1 power density and outstanding capacity retention (92% after 5000 cycles). The experimental findings for the oxygen evolution reaction reveal that the initial increase in potential required for MgCuPO4-Ag3PO4 is 142 mV, indicating a clear Tafel slope of 49 mV dec-1.

3.
Molecules ; 28(13)2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37446811

RESUMEN

The utilization of biochar, derived from agricultural waste, has garnered attention as a valuable material for enhancing soil properties and serving as a substitute adsorbent for the elimination of hazardous heavy metals and organic contaminants from wastewater. In the present investigation, amide-modified biochar was synthesized via low-temperature pyrolysis of rice husk and was harnessed for the removal of Cr(VI) from wastewater. The resultant biochar was treated with 1-[3-(trimethoxysilyl) propyl] urea to incorporate an amide group. The amide-modified biochar was characterized by employing Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. During batch experiments, the effect of various parameters, such as adsorbent dosage, metal concentration, time duration, and pH, on Cr(VI) removal was investigated. The optimal conditions for achieving maximum adsorption of Cr(VI) were observed at a pH 2, an adsorbent time of 60 min, an adsorbent dosage of 2 g/L, and a metal concentration of 100 mg/L. The percent removal efficiency of 97% was recorded for the removal of Cr(VI) under optimal conditions using amide-modified biochar. Freundlich, Langmuir, and Temkin isotherm models were utilized to calculate the adsorption data and determine the optimal fitting model. It was found that the adsorption data fitted well with the Langmuir isotherm model. A kinetics study revealed that the Cr(VI) adsorption onto ABC followed a pseudo-second-order kinetic model. The findings of this study indicate that amide-functionalized biochar has the potential to serve as an economically viable substitute adsorbent for the efficient removal of Cr(VI) from wastewater.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Amidas , Contaminantes Químicos del Agua/química , Carbón Orgánico/química , Cromo/química , Adsorción , Cinética , Concentración de Iones de Hidrógeno
4.
ACS Omega ; 8(22): 19892-19899, 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37305269

RESUMEN

In this work, the new compositions of FeCoNiAlMn1-xCrx, (0.0 ≤ x ≤ 1.0), a high-entropy alloy powder (HEAP), are prepared by mechanical alloying (MA). The influence of Cr doping on the phase structure, microstructure, and magnetic properties is thoroughly investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometry. It is found that this alloy has formed a simple body-centered cubic structure with a minute face-centered cubic structure for Mn to Cr replacement with heat treatment. The lattice parameter, average crystallite size, and grain size decrease by replacing Cr with Mn. The SEM analysis of FeCoNiAlMn showed no grain boundary formation, depicting a single-phase microstructure after MA, similar to XRD. The saturation magnetization first increases (68 emu/g) up to x = 0.6 and then decreases with complete substitution of Cr. Magnetic properties are related to crystallite size. FeCoNiAlMn0.4Cr0.6 HEAP has shown optimum results with better saturation magnetization and coercivity as a soft magnet.

5.
RSC Adv ; 13(21): 14530-14538, 2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-37188253

RESUMEN

Arsenic (As3+) is the most carcinogenic and abundantly available heavy metal present in the environment. Vertically aligned ZnO nanorod (ZnO-NR) growth was achieved on metallic nickel foam substrate via a wet chemical route and it was used as an electrochemical sensor towards As(iii) detection in polluted water. Crystal structure confirmation, surface morphology observation and elemental analysis of ZnO-NRs were conducted using X-ray diffraction, field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. Electrochemical sensing performance of ZnO-NRs@Ni-foam electrode/substrate was investigated via linear sweep voltammetry, cyclic voltammetry and electrochemical impedance spectroscopy in a carbonate buffer solution of pH = 9 and at different As(iii) molar concentrations in solution. Under optimum conditions, the anodic peak current was found proportional to the arsenite concentration from 0.1 µM to 1.0 µM. The achieved values for limit of detection and limit of quantification were 0.046 ppm and 0.14 ppm, respectively, which are far lower than the recommended limits for As(iii) detection in drinking water as suggested by the World Health Organization. This suggests that ZnO-NRs@Ni-foam electrode/substrate can be effectively utilized in terms of its electrocatalytic activity towards As3+ detection in drinking water.

6.
ACS Omega ; 8(20): 17779-17787, 2023 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-37251136

RESUMEN

In the present work, several properties of fluoroperovskites are computed and examined through the approximations of trans- and blaha-modified Becke-Johnson (TB-mBJ) and generalized gradient approximation of Perdew-Burke-Ernzerhof (GGA-PBE) integrated within density functional theory (DFT). The lattice parameters for cubic TlXF3 (X = Be, Sr) ternary fluoroperovskite compounds at an optimized state are examined and their values are used to calculate the fundamental physical properties. TlXF3 (X = Be and Sr) cubic fluoroperovskite compounds contain no inversion symmetry and are thus a non-centrosymmetric system. The phonon dispersion spectra confirm the thermodynamic stability of these compounds. The results of electronic properties clarify that both the compounds possess a 4.3 eV of indirect band gap from M-X for TlBeF3 and a direct band gap of 6.03 eV from X-X for TlSrF3, which display that both compounds are insulators. Furthermore, the dielectric function is considered to explore optical properties like reflectivity, refractive index, absorption coefficient, etc., and the different types of transitions between the bands were investigated by using the imaginary part of the dielectric function. Mechanically, the compounds of interest are computed to be stable and possess high bulk modulus values, and the ratio of "G/B" is higher than "1", which indicates the strong and ductile nature of the compound. Based on our computations for the selected materials, we deem an efficient application of these compounds in an industrial application, which will provide a reference for future work.

7.
RSC Adv ; 12(46): 29627-29639, 2022 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-36321093

RESUMEN

1,3,4-Thiadiazole molecules (1-4) were synthesized by the reaction of phenylthiosemicarbazide and methoxy cinnamic acid molecules in the presence of phosphorus oxychloride, and characterized with UV, FT-IR, 13C-NMR, and 1H-NMR methods. DFT calculations (b3lyp/6-311++G(d,p)) were performed to investigate the structures' geometry and physiochemical properties. Their antibacterial activity was screened for various bacteria strains such as Enterobacter aerogenes, Escherichia coli ATCC 13048, Salmonella kentucky, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus and Gram positive such as Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 7644, Enterococcus faecium, Enterococcus durans, Staphylococcus aureus ATCC, Serratia marcescens, Staphylococcus hominis, Staphylococcus epidermidis, alfa Streptococcus haemolyticus, Enterococcus faecium and found to have an inhibitory effect on Klebsiella pneumoniae and Staphylococcus hominis, while molecules 1, 3 and 4 had an inhibitory effect on Staphylococcus epidermidis and alpha Streptococcus haemolyticus. The experimental results were supported by the docking study using the Kinase ThiM from Klebsiella pneumoniae. All the investigated compounds showed an inhibitory effect for the Staphylococcus epidermidis protein. In addition, the mechanism of the 1-4 molecule interaction with calf thymus-DNA (CT-DNA) was investigated by UV-vis spectroscopic methods.

8.
ACS Omega ; 7(40): 35743-35754, 2022 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-36249408

RESUMEN

A new series of spirooxindoles based on ethylene derivatives having furan aryl moiety are reported. The new hybrids were achieved via [3 + 2] cycloaddition reaction as an economic one-step efficient approach. The final constructed spirooxindoles have four contiguous asymmetric carbon centers. The structure of 3a is exclusively confirmed using X-ray single crystal diffraction. The supramolecular structure of 3a is controlled by O···H, H···H, and C···C intermolecular contacts. It includes layered molecules interconnected weak C-H···O (2.675 Å), H···H (2.269 Å), and relatively short Cl···Br interhalogen interactions [3.4500(11)Å]. Using Hirshfeld analysis, the percentages of these intermolecular contacts are 10.6, 25.7, 6.4, and 6.2%, respectively. The spirooxindoles along with ethylene derivatives having furan aryl moiety were assessed against breast (MCF7) and liver (HepG2) cancer cell lines. The results indicated that the new chalcone 3b showed excellent activity in both cell lines (MCF7 and HepG2) with IC50 = 4.1 ± 0.10 µM/mL (MCF7) and 3.5 ± 0.07 µM/mL (HepG2) compared to staurosporine with 4.3 and 2.92 folds. Spirooxindoles 6d (IC50 = 4.3 ± 0.18 µM/mL), 6f (IC50 = 10.3 ± 0.40 µM/mL), 6i (IC50 = 10.7 ± 0.38 µM/mL), and 6j (IC50 = 4.7 ± 0.18 µM/mL) exhibited potential activity against breast adenocarcinoma, while compounds 6d (IC50 = 6.9 ± 0.23 µM/mL) and 6f (IC50 = 3.5 ± 0.11 µM/mL) were the most active hybrids against human liver cancer cell line (HepG2) compared to staurosporine [IC50 = 17.8 ± 0.50 µM/mL (MCF7) and 10.3 ± 0.23 µM/mL (HepG2)]. Molecular docking study exhibited the virtual mechanism of binding of compound 3b as a dual inhibitor of EGFR/CDK-2 proteins, and this may highlight the molecular targets for its cytotoxic activity.

9.
J Chromatogr A ; 1684: 463534, 2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36242793

RESUMEN

Peptides and proteins have great therapeutic potential, and owing to their unique biological properties, their separation is very challenging. A polar embedded C18 stationary phase was prepared by functionalization of porous silica monolith particles with N-3-(trimethoxysilyl) propyl stearamide. The stationary phase was packed in narrow bore column (100 × 2.1 mm) and evaluated for the separation of peptides and proteins in HPLC. Number of theoretical plates (N) as high as 520,000 and 340,000 plates/meter were obtained for peptides and proteins respectively. The separation performance of C18-amide column was compared with four commercial amide columns i.e. Ascentis Express RP-Amide, Accucore 150 Amide, TSKgel Amide-80, and XBridge Amide column. The performance of C18-amide column was much better than these commercial amide columns in terms of efficiency and resolution. Owing to high efficiency and good resolution for peptides and proteins separation, C18-amide column could be used as alternative to expansive commercial columns.


Asunto(s)
Péptidos , Proteínas , Cromatografía Líquida de Alta Presión/métodos , Dióxido de Silicio/química , Amidas/química
10.
Molecules ; 27(13)2022 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35807340

RESUMEN

In the present work, a novel heterocyclic hybrid of a spirooxindole system was synthesized via the attachment of ferrocene and triazole motifs into an azomethine ylide by [3 + 2] cycloaddition reaction protocol. The X-ray structure of the heterocyclic hybrid (1″R,2″S,3R)-2″-(1-(3-chloro-4-fluorophenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl)-5-methyl-1″-(ferrocin-2-yl)-1″,2″,5″,6″,7″,7a″-hexahydrospiro[indoline-3,3″-pyrrolizin]-2-one revealed very well the expected structure, by using different analytical tools (FTIR and NMR spectroscopy). It crystallized in the triclinic-crystal system and the P-1-space group. The unit cell parameters are a = 9.1442(2) Å, b = 12.0872(3) Å, c = 14.1223(4) Å, α = 102.1700(10)°, ß = 97.4190(10)°, γ = 99.1600(10)°, and V = 1484.81(7) Å3. There are two molecules per unit cell and one formula unit per asymmetric unit. Hirshfeld analysis was used to study the molecular packing of the heterocyclic hybrid. H···H (50.8%), H···C (14.2%), Cl···H (8.9%), O···H (7.3%), and N···H (5.1%) are the most dominant intermolecular contacts in the crystal structure. O···H, N···H, H···C, F···H, F···C, and O···O are the only contacts that have the characteristic features of short and significant interactions. AIM study indicated predominant covalent characters for the Fe-C interactions. Also, the electron density (ρ(r)) at the bond critical point correlated inversely with the Fe-C distances.


Asunto(s)
Triazoles , Cristalografía por Rayos X , Reacción de Cicloadición , Espectroscopía de Resonancia Magnética , Metalocenos
11.
Polymers (Basel) ; 14(13)2022 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35808622

RESUMEN

Separation with high efficiency and good resolution is constantly in demand in the pharmaceutical industry. The fast and efficient separation of complex samples such as peptides and proteins is a challenging task. To achieve high efficiency with good resolution, chromatographers are moving towards small particles packed into narrow-bore columns. Silica monolith particles (sub-2 µm) were derivatized with chlorodimethyl octadecyl silane (C18) and packed into stainless steel columns (100 mm × 1.8 mm i.d) by a slurry-packing method. The developed columns were used for the separation of peptides and proteins. A separation efficiency (N) of 40,000 plates/column (400,000 plates/m) was achieved for the mixture of five peptides. Similarly, the fast separation of the peptides was carried out using a high flow rate, and the separation of the five peptides was achieved in one minute with high efficiency (N ≅ 240,000 plates/m). The limit of detection (DL) and the limit of quantification (QL) for each analyte were determined by developing a linear regression curve with relatively very low concentrations of the target compound. The average values of the QL for the peptide and proteins were 0.55 ng and 0.48 ng, respectively, using short C18 column (1.8 mm × 100 mm) UV (at 214 nm). The fast analysis of peptides and proteins with such high efficiency and good resolution has not been reported in the literature yet. Owing to high efficiency, these home-made columns could be used as an alternative to the expensive commercial columns for peptide and protein separation.

12.
Talanta ; 246: 123540, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35588645

RESUMEN

A novel antibacterial quinolone was prepared with two chiral centers. For medicinal safety purposes, the four stereoisomers of the molecule are separated by HPLC using a Chiral (+)-Crownpack column (25 cm × 0.46 cm, 5.0 µm) with an eluent of 50 mM H2SO4. The values of the retention, separation, and resolution factors of RR-, SS-, RS-, and SR-stereoisomers were in the range of 1.15-7.55, 1.18 to 2.34, and 1.05 to 2.38 at 15, 20, 25, 30 and 35 °C temperatures. The values of the linearity, limits of detection, and limits of quantitation were in the range of 55.6-125, 1.5 to 4.0, and 14.0-37.6 µg mL-1. Chiral HPLC separation was validated properly. The thermodynamics parameters were in the range of 1.96-10.72 kJ mol-1 (ΔΔH), 0.013-0.041 kJ mol-1K-1 (ΔΔS) and -0.52 to -1.99 kJ mol-1K-1 (ΔG298). These values confirmed chiral separation as spontaneous and thermodynamically stable. The simulation study was used to understand the mechanism of the chiral separation at the supramolecular level. The binding affinities of the stereoisomers with the chiral stationary phase were in the range of -3.0 to -3.5 kcal mol-1. The hydrogen bonding was found responsible for the chiral separation. The reported HPLC conditions are inexpensive and may be used to separate the four stereoisomers successfully in any sample.


Asunto(s)
Quinolonas , Cromatografía Líquida de Alta Presión , Simulación por Computador , Estereoisomerismo , Termodinámica
13.
Environ Res ; 201: 111429, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34146527

RESUMEN

Effective improvement of an easily recoverable photocatalyst is equally vital to its photocatalytic performance from a practical application view. The magnetically recoverable process is one of the easiest ways, provided the photocatalyst is magnetically strong enough to respond to an external magnetic field. Herein, we prepared graphitic carbon nitride nanosheet (g-C3N4), and ZnS quantum dots (QDs) supported ferromagnetic CoFe2O4 nanoparticles (NPs) as the gC3N4/ZnS/CoFe2O4 nanohybrid photocatalyst by a wet-impregnation method. The loading of CoFe2O4 NPs in the g-C3N4/ZnS nanohybrid resulted in extended visible light absorption. The ferromagnetic g-C3N4/ZnS/CoFe2O4 nanohybrid exhibited better visible-light-active photocatalytic performance (97.11%) against methylene blue (MB) dye, and it was easily separable from the aqueous solution by an external bar magnet. The g-C3N4/ZnS/CoFe2O4 nanohybrid displayed excellent photostability and reusability after five consecutive cycles. The favourable band alignment and availability of a large number of active sites affected the better charge separation and enhanced photocatalytic response. The role of active species involved in the degradation of MB dye during photocatalyst by g-C3N4/ZnS/CoFe2O4 nanohybrid was also investigated. Overall, this study provides a facile method for design eco-friendly and promising g-C3N4/ZnS/CoFe2O4 nanohybrid photocatalyst as applicable in the eco-friendly dye degradation process.


Asunto(s)
Iluminación , Nanocompuestos , Catálisis , Luz , Fotólisis , Sulfuros , Compuestos de Zinc
14.
J Sep Sci ; 44(13): 2602-2611, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33905621

RESUMEN

Mixed-mode chromatography open tubular column has been developed for peptide separation in electrochromatography. A column with 92 cm effective length and 50 µm internal diameter is fabricated internally with a copolymer sheet of restricted thickness. Catalyst facilitated binding of the coupling agent 3,5-bis (trifluoromethyl) phenyl isocyanate has been carried out at the interior surface of the column. The initiator sodium diethyldithiocarbamate was bound to the coupling agent. A small amount of N-[2-(acryloylamino) phenyl] acrylamide was used along with methacrylic acid and styrene in the monomer mixture to induce a little polar character in the stationary phase fabricated inside the column. Twenty-three peptides have been separated from a chemically digested protein mixture present in cytochrome C in capillary electrochromatography, in addition to the separation of six commercial peptides. We achieved an average plate count of over 1.5 million/m with the column of current study both for the digested protein components and commercial peptides using 70/30% v/v (acetonitrile/20 mM ammonium formate) at pH 6.5. In addition, the column resulted in baseline separation of all the peptides with very good resolution, enhanced peak capacity, and better retention time span.


Asunto(s)
Electrocromatografía Capilar/métodos , Proteómica/métodos , Péptidos/análisis
15.
Environ Res ; 197: 111079, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33775684

RESUMEN

In this study, 2D/2D/2D heterostructured r-GO/LTH/ZnO/g-C3N4 nanohybrid were synthesized through hydrothermal method. The strong electrostatic interaction between the negatively charged g-C3N4 and r-GO nanosheets with positively charged layered triple hydroxide (LTH) nanosheets are effectively influences the successful formation of heterojunction. The LTH nanosheets are well spread on the g-C3N4 nanosheets combined with r-GO. In particular, the as prepared heterojunction shows a better photocatalytic degradation activity compared to pristine samples and the significant enhancement in the photocatalytic performance is mainly accredited to the large interfacial charge transition of photogenerated charge carriers under the visible light irradiation. Although the 2D/2D/2D heterojunction effectively hinders the charge carrier recombination resulting high photocatalytic activity with good stability. In addition, the r-GO supported LTH/ZnO/g-C3N4 heterojunction shows high photo-stability after sequential experimental runs with no obvious change in the dye degradation process. Consequently, the role of active species was investigated over the r-GO/LTH/ZnO/g-C3N4 heterojunction with the help of different scavengers.


Asunto(s)
Óxido de Zinc , Catálisis , Grafito , Hidróxidos , Luz
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 237: 118332, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32371354

RESUMEN

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.


Asunto(s)
Ezetimiba/análisis , Inhibidores de Hidroximetilglutaril-CoA Reductasas/análisis , Hipolipemiantes/análisis , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Atorvastatina/análisis , Combinación de Medicamentos , Tecnología Química Verde/métodos , Límite de Detección , Reproducibilidad de los Resultados , Rosuvastatina Cálcica/análisis , Simvastatina/análisis , Comprimidos/análisis
17.
Saudi Pharm J ; 20(3): 255-62, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24115904

RESUMEN

Two highly sensitive and simple spectrophotometric methods were developed to quantitate the drug cyclizine (CYC) in its pure form and in a pharmaceutical formulation. The two methods involved ion-associate formation reactions (method A) with mono-acid azo dyes, i.e., sudan (I) and sudan (II), as well as ion-pair reactions (method B) with bi-azo dyes, i.e., sudan (III), sudan (IV) and sudan red 7B (V). The reactions were extracted with chloroform, and the extraction products were quantitatively measured at 480, 550, 500, 530 and 570 nm using reagents I-V, respectively. The reaction conditions were monitored and optimised. The Beer plots for reagents I-V showed linear relationships for the concentrations of 4.2-52.0, 5.4-96.0, 3.5-43.0, 4.4-80.0 and 0.6-18.0 µg mL(-1), respectively, with molar absorptivities of 2.2 × 10(4), 4.1 × 10(4), 3.6 × 10(4), 2.5 × 10(4) and 1.3 × 10(4) L mol(-1) cm(-1), respectively. Sandell sensitivities and detection limits were calculated and analysed. The implementation of the two methods to the analysis of a commercial tablet (Valoid) succeeded, and the recovery study suggested that there was no interference from common excipients in the tablet. Regarding the accuracy and precision of the methods, a statistical comparison of the results was performed using Student's t-test and the F-test at the 95% confidence level. The accuracy and precision of the proposed methods were not significantly different.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...