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Pharmacia ◽  
2022 ◽  
Vol 69 (1) ◽  
pp. 61-67
Author(s):  
Nataliia Shulyak ◽  
Kateryna Liushuk ◽  
Oksana Semeniuk ◽  
Nadiya Yarema ◽  
Tetyana Uglyar ◽  
...  

Atorvastatin and lisinopril are a successful combination for the treatment of patients with chronic heart failure and hypertension. Study of the dissolution kinetics of drugs in solid dosage form with lisinopril and atorvastatin and intestinal permeability to assess their equivalence in vitro were described. In medium with hydrochloric acid pH 1.2, in the medium of acetate buffer solution with a pH of 4.5 and in the medium phosphate buffer solution with a pH of 6.8 for 15 min more than 85% of the active substance passes into solution, hence the dissolution profiles these drugs in these environments are similar, and the drugs in them are “very quickly soluble”. Among the in vitro models that make it possible to assess the degree of absorption of API, the most widely used culture of adenocarcinoma cells of the colon – Caco-2. The development of the analytical methodology and its validation is the final stage of both the dissolution study and the Caco-2 test, as well as the biowaver procedure. It plays the most important role in the reliability of the results for all the above procedures and tests. To study permeability, method LC-MS/MS was developed. According to the obtained results, atorvastatin and lisinopril showed low permeability. The values ​​of recovery of transport of test and control substances through the monolayer of cells of the Caco-2 line indicate that the results of the experiment can be considered reliable. The equivalence of the drugs “Lisinopril”, tablets of 10 mg and “Atorvastatin”, tablets of 10 mg, belongs to class III BCS proven by in vitro studies.


2022 ◽  
Author(s):  
Srikanth Ponnada ◽  
Demudu Babu Gorle ◽  
Maryam Sadat Kiai ◽  
Venkateswara raju Chikkili ◽  
M. Faraji ◽  
...  

A pioneering CuBTABB-MOF/rGO composite customized electrode is fabricated and utilized as a sensor towards identifying Bisphenol A (BPA) ina phosphate buffer solution of pH7.0. Composite is characterized by FTIR, Raman...


2021 ◽  
Author(s):  
Shunsuke Yamada

An environmentally benign supercapacitor is developed incorporating an ionic liquid, carbon powder, a cellulose separator and a Molybdenum electrode. The ionic liquid is dispersed into a water-dissolvable polymer, poly(vinyl alcohol), to produce solid electrolyte, so-called an ionic gel. A carbon composite mixed with the ionic liquid maintains a gel form. The ionic gel and the carbon composite enable an all-solid-state supercapacitor which can be charged at the voltage of 1.5 V. The supercapacitor shows areal and volumetric capacitance of 65 mF/cm2 and 2.2 F/cm3. A cycle test reveals that capacitance retention and coulombic efficiency are 77% and 90%, respectively. As for dissolution test, the ionic gel and carbon composite dissolves into phosphate buffer solution in 18 days, and the Mo electrode is able to fully dissolve in 500~588 days. Potential applications of the environmentally benign supercapacitor include smart agriculture by monitoring of soil, disaster prevention by the wireless sensor network without need for retrieval of devices after use.


2021 ◽  
Vol 68 (4) ◽  
pp. 1027-1032
Author(s):  
Pınar Talay Pınar ◽  
Yavuz Yardım ◽  
Zühre Şentürk

In this reported work, an anodically pretreated boron-doped diamond (BDD) electrode was used for the inexpensive, simple and quick detection of a natural dye, lawsone. Lawsone had a well-defined, irreversible and diffusion-controlled oxidation peak at approximately +0.19 V in phosphate buffer solution (PBS, 0.1 M, pH 2.5) using cyclic voltammetry (CV). The oxidation peak heights of lawsone were significantly increased in PBS using the cationic surfactant cetyltrimethylammonium bromide (CTAB). Under optimized experimental conditions, the calibration curve was linear over a concentration range of 0.1–5.0 μM with detection limit of 0.029 μM in 0.1 M PBS (pH 2.5) containing 0.1 mM CTAB by using square-wave voltammetry (SWV). To evaluate the practical applicability of the BDD electrode, it was used for the quantification of lawsone in commercial henna, a natural dye made from the leaves of the henna plant.


Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1966
Author(s):  
Ikuo Nakanishi ◽  
Yoshimi Shoji ◽  
Kei Ohkubo ◽  
Shunichi Fukuzumi

Recently, increasing attention has been paid to quantum mechanical behavior in biology. In this study, we investigated the involvement of quantum mechanical tunneling in the hydrogen-transfer reaction from Trolox, a water-soluble analog of vitamin E (α-tocopherol), to 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) in a phosphate buffer solution (0.05 M, pH 7.0). DPPH• was used as a reactivity model of reactive oxygen species and solubilized in water using β-cyclodextrin (β-CD). The second-order rate constants, kH and kD, in 0.05 M phosphate buffer solutions prepared with H2O (pH 7.0) and D2O (pD 7.0), respectively, were determined for the reaction between Trolox and DPPH•, using a stopped-flow technique at various temperatures (283–303 K). Large kinetic isotope effects (KIE, kH/kD) were observed for the hydrogen-transfer reaction from Trolox to the β-CD-solubilized DPPH• in the whole temperature range. The isotopic ratio of the Arrhenius prefactor (AH/AD = 0.003), as well as the isotopic difference in the activation energies (19 kJ mol−1), indicated that quantum mechanical tunneling plays a role in the reaction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takio Inatomi ◽  
Mihoko Honma

AbstractThe role of probiotics in mitigating constipation, gut immunity, and gut microbiota has not been well studied. We aimed to evaluate the effects of probiotics on loperamide (LP)-induced constipation in Sprague–Dawley rats. Altogether, 150 male Sprague–Dawley rats (age 8 weeks) were used in the experiments following a 12-day acclimatisation period and were randomly divided into three treatment groups (groups 1, 2, and 3). Spastic constipation was induced via oral LP administration (3 mg/kg) for 6 days, 1 h before administering each test compound in groups 1 and 2. A probiotic solution (4 mL/kg body weight) was orally administered once a day for 6 days in group 2. In group 1, a phosphate buffer solution was orally administered once a day for 6 days, 1 h after each LP administration. In group 3, a phosphate buffer solution was orally administered once a day for 6 days. In the probiotic group, faecal parameters improved; faecal n-butyric acid, acetic acid, and IgA concentrations were increased; intestinal transit time was shortened; and disturbance of intestinal microbiota was inhibited. Our findings suggest that this probiotic was useful in improving various symptoms caused by constipation.


2021 ◽  
Author(s):  
Ebrahim Nabatian ◽  
Mahdi Mousavi ◽  
Mostafa Pournamdari ◽  
Saeid Ahmadzadeh

Abstract A simple and precise analytical approach developed for single and simultaneous determination of resorcinol (RC) and hydroquinone (HQ) in pharmaceutical samples using carbon paste electrode (CPE) modified with 1-Ethyl-3-methylimidazolium tetrafluoroborate as ionic liquid and ZnFe2O4 nanoparticle. A significant enhancement in the peak current and sensitivity of the proposed sensor observed by using modifiers in the composition of working electrode compared to bare CPE which is in accordance with the results obtained from electrochemical impedance spectroscopy investigations. Electrochemical investigations revealed a well-defined irreversible oxidation peak for RC over a wide concentration range from 3.0 µM to 500 µM in 0.1 M phosphate buffer solution (pH 6.0) with the linear regression equations of Ip (µA) = 0.0276 CRC (µM) + 0.5508 (R2 = 0.997). The limit of detection and quantification for RC analysis were found to be 1.46 µM and 4.88 µM, respectively. However, the obtained SW voltammograms for simultaneous determination of RC and HQ exhibited a desirable peak separation of about 360 mV potential difference and a satisfactory linear response over the range of 50-700 µM and 5-350 µM with the favorable correlation coefficient of 0.991 and 0.995, respectively. The diffusion coefficient (D) of RC and the electron transfer coefficient (α) at the surface of ZnFe2O4/NPs/IL/CPE estimated to be 2.83×10−4 cm s−1 and 0.76. The proposed sensor as a promising and low-cost method successfully applied for determination of RC in commercial pharmaceutical formulations such as the resorcinol cream of 2% O/W emulsion available on the market with the recovery of 98.47±0.04.


Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 235
Author(s):  
Mohammed M. Rahman ◽  
Jahir Ahmed ◽  
Abdullah M. Asiri ◽  
Sulaiman Y.M. Alfaifi ◽  
Hadi. M. Marwani

Herein, novel Co3O4·CdO·ZnO-based tri-metallic oxide nanoparticles (CCZ) were synthesized by a simple solution method in basic phase. We have used Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscope (FESEM), Dynamic Light Scattering (DLS), Tunneling Electron Microscopy (TEM), and Energy-Dispersive Spectroscopy (EDS) techniques to characterize the CCZ nanoparticles. XRD, TEM, DLS, and FESEM investigations have confirmed the tri-metallic nanoparticles’ structure, while XPS and EDS analyses have shown the elemental compositions of the CCZ nanoparticles. Later, a Au/μ-Chip was modified with the CCZ nanoparticles using a conducting binder, PEDOT: PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) in a sol-gel system, and dried completely in air. Then, the CCZ/Au/μ-Chip sensor was used to detect methanol (MeOH) in phosphate buffer solution (PBS). Outstanding sensing performance was achieved for the CCZ/Au/μ-Chip sensor, such as excellent sensitivity (1.3842 µAµM−1cm−2), a wide linear dynamic range of 1.0 nM–2.0 mM (R2 = 0.9992), an ultra-low detection limit (32.8 ± 0.1 pM at S/N = 3), a fast response time (~11 s), and excellent reproducibility and repeatability. This CCZ/Au/μ-Chip sensor was further applied with appropriate quantification results in real environmental sample analyses.


Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3998
Author(s):  
Mohammed M. Rahman ◽  
M. M. Alam ◽  
Sulaiman Y. M. Alfaifi ◽  
Abdullah M. Asiri ◽  
Meser M. Ali

In this research study, we developed a voltammetric electrochemical sensor probe with a copolymer Nafion (Sulfonated Tetrafluoroethylene-based Fluoro-polymer) decorated with hydrothermally prepared sandwich-type CuO/ZnO nanospikes (NSs) onto a glassy carbon electrode (GCE) for reliable thiourea (TU) detection. The detailed characterizations in terms of structural morphology, binding energy, elemental compositions, grain size and crystallinity for synthesized NSs were performed by field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis, respectively. The differential pulse voltammetric (DPV) analysis for TU showed good linearity at current-versus-TU concentration on the calibration plot in the 0.15~1.20 mM range, which is defined as a dynamic detection range (LDR) of TU in a phosphate buffer solution. Considering the slope of LDR over the GCE-coated NSs surface area (0.0316 cm2), the TU sensor sensitivity (0.4122 µA µM−1 cm−2) was obtained. Besides this, the low limit (LOD) for TU detection was calculated and found to be 23.03 ± 1.15 µM. The fabricated Nafion/CuO/ZnO NSs/GCE sensor probe was created as a reliable sensor based on reproducibility, interference effect, stability and response time. Real bio-samples were investigated and the results confirm the anticipated reliability of the TU sensor probe. Thus, this is a noble way to develop enzyme-free electrochemical sensors that could be an alternative approach for the detection of chemicals in the field of enzyme-free biosensor development technology.


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