scholarly journals Cyclodextrin-Efavirenz Complexes Investigated by Solid State and Solubility Studies

Proceedings ◽  
2020 ◽  
Vol 78 (1) ◽  
pp. 15
Author(s):  
Susana Santos Braga ◽  
Karyna Lysenko ◽  
Firas El-Saleh ◽  
Filipe A. Almeida Paz
Keyword(s):  
Solid State ◽  
Transcriptase Inhibitor ◽  
Water Soluble ◽  
Short Paper ◽  
Solid Inclusion ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Co Precipitation ◽  
Reverse Transcriptase Inhibitor

This short paper investigates the solubilizing ability of various cyclodextrins with efavirenz as well as the formation of solid inclusion complexes of efavirenz with β-CD and γ-CD. (1) Background: Efavirenz is a non-nucleoside reverse transcriptase inhibitor used as first-line treatment for adult and pediatric human immunodeficiency virus type 1 infection (HIV-1). Belonging to class II of Biopharmaceutical Classification System (BCS), efavirenz is poorly water-soluble. Inclusion into cyclodextrins is a possible strategy for increasing its solubility. (2) Methods: Solubility modulation was investigated by the phase solubility method; inclusion of efavirenz with β- and γ-cyclodextrins was attempted by co-dissolution with co-precipitation; the precipitates were studied by DSC, FT-IR, powder X-ray diffraction and optical microscopy. (3) Results: Solid state analysis of the precipitates shows evidence of separate recrystallization of β-cyclodextrin and efavirenz, whereas in the case of γ-cyclodextrin, a single new phase was observed. (4) Conclusion: Results show that the cavity of β-cyclodextrin is too narrow to accommodate efavirenz and only γ-cyclodextrin, the largest of native cyclodextrins, is able to form a true inclusion complex with this bulky guest.

scholarly journals Native Cyclodextrins as Complexation Agents for Pterostilbene: Complex Preparation and Characterization in Solution and in the Solid State

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 8
Author(s):  
Laura Catenacci ◽  
Alexios I. Vicatos ◽  
Milena Sorrenti ◽  
Maria Cristina Bonferoni ◽  
Mino R. Caira
Keyword(s):  
Solid State ◽  
Complex Formation ◽  
Aqueous Solubility ◽  
Molar Ratio ◽  
Phase Solubility ◽  
Scanning Calorimetry ◽  
Complex Preparation ◽  
Ft Ir ◽  
Sugar Levels ◽  
Co Precipitation

Pterostilbene (3,5-dimethoxy-4′-hydroxystilbene, PTB) is a natural dietary stilbene, occurring primarily in blueberries and Pterocarpus marsupium heartwood. The interest in this compound is related to its different biological and pharmacological properties, such as its antioxidant, anti-inflammatory, and anticarcinogenic activities and its capacity to reduce and regulate cholesterol and blood sugar levels. Nevertheless, its use in therapy is hindered by its low aqueous solubility; to overcome this limitation we studied the feasibility of the use of cyclodextrins (CDs) as solubility-enhancing agents. CDs are natural macrocyclic oligomers composed of α-d-glucose units linked by α-1,4 glycosidic bonds to form torus-shaped molecules, responsible for inclusion complex formation with organic molecules. In particular, the aim of this study was to evaluate the feasibility of complexation between PTB and native CDs using various preparative methods. The isolated solid products were characterized using differential scanning calorimetry (DSC), simultaneous thermogravimetric/DSC analysis (TGA/DSC), Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) on powder and single crystals. The results indicated little or no evidence of the affinity of PTB to complex with α-CD using the kneading method. However, with β-CD and γ-CD thermal analysis revealed an interaction which was also corroborated by FT-IR and 1H-NMR spectroscopy. With β-CD, a hydrated complex of PTB was isolated and its characterization by single-crystal XRD revealed, for the first time, the mode of inclusion of the PTB molecule in the cavity of a CD. To complement the solid-state data, liquid-phase studies were carried out to establish the effect of CDs on the aqueous solubility of PTB and to determine the complex stoichiometries and the association constants for complex formation. Phase-solubility studies showed AL-type profiles for α- and β-CD and a BS profile for γ-CD, with K1:1 values of 1144, 4950, and 133 M−1 for α-CD·PTB, β-CD·PTB, and γ-CD·PTB, respectively. The stoichiometry of CD·PTB complexes, determined by Job’s method, revealed for each system a 1:1 molar ratio. The dissolution rate of PTB was approximately doubled just by employing simple physical mixtures, but the best performance was achieved by products obtained via kneading and co-precipitation, which effected the complete dissolution of PTB in 40 and 20 min for β-CD and γ-CD, respectively.

Preparation and Photocatalytic Activity of Cu/BiVO4 by Solid State Grinding Method for Degradation of Methyl Orange

2016 ◽  
Vol 703 ◽  
pp. 321-325
Author(s):  
Hai Feng Chen ◽  
Jia Mei Chen ◽  
Zhi Xue Pan
Keyword(s):  
Methyl Orange ◽  
Solid State ◽  
Visible Light ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Illumination Time ◽  
Grinding Method ◽  
Ft Ir ◽  
Degradation Of Methyl Orange

In this work, novel Cu/BiVO4 photocatalyst were prepared by a low-temperature solid state grinding method using Bi (NO3)3•5H2O, NH4VO3 and Cu (NO3)2•2H2O as raw materials. The structure and properties of the samples were characterized by Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and UV-vis diffused reflectance spectroscopy (DRS); Using the degradation of methyl orange (MO) as the probe, it was simulated as the degradation of sewage under the visible light to study the influence of the illumination time and the amount of photocatalysts. Compared with the pure BiVO4, the visible-light absorption scope of BiVO4 was broadened by doping Cu, the UV-Visible absorption edges were slightly red shift and the band gap was narrower. Comparatively speaking, the results indicted that the doped Cu enhanced the photocatalytic activities of BiVO4.

Synthesis of Silica Modified Large-Sized Hydroxyapatite Whiskers by a Hydrothermal Co-Precipitation Method

2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen
Keyword(s):  
Bone Repair ◽  
Ethanol Solution ◽  
Morphological Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Ft Ir ◽  
Co Precipitation ◽  
Surface Modified

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers

scholarly journals Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

2017 ◽  
Vol 13 ◽  
pp. 2138-2145 ◽  
Author(s):  
Joana M Pais ◽  
Maria João Barroca ◽  
Maria Paula M Marques ◽  
Filipe A Almeida Paz ◽  
Susana S Braga
Keyword(s):  
Inclusion Compound ◽  
Antioxidant Properties ◽  
Physicochemical Analysis ◽  
Water Soluble ◽  
Solid Inclusion ◽  
Human Consumption ◽  
X Ray Diffraction ◽  
Wide Range ◽  
Soluble Solid ◽  
Cp Mas Nmr

Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD), a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD), Raman, infrared and 13C{1H} CP-MAS NMR spectroscopies, and thermal analysis (TGA) to verify fisetin inclusion and to present a hypothetical structural arrangement for the host–guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

Synthesis of Magnetic Modified Organobentonite as Adsorbent for Degradation of Orange II

2013 ◽  
Vol 838-841 ◽  
pp. 2306-2309
Author(s):  
Guang Hua Wang ◽  
Kun Chen ◽  
Wen Bing Li ◽  
Dong Wan ◽  
Qin Hu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Reaction Medium ◽  
Precipitation Method ◽  
Basal Spacing ◽  
Orange Ii ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Co Precipitation ◽  
Scanning Electron

Magnetic modified organobentonite (Fe3O4/CTAB–Bent) was synthesized by chemical co-precipitation method in which CTAB–Bent was firstly achieved via ion–exchange.The composite materials have been characterized by powder X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR) and Scanning electron microscopy (SEM) . The results revealed that basal spacing of bentonite was increased through organic modification and the Fe3O4 particles synthesized which covering the surfaces of bentonite .Compared with natural bentonite, the adsorption capacity of Fe3O4/CTAB–Bent for Orange II was greatly enhanced and can be easily separated from the reaction medium by an external magnetic field after the treatment.

An Investigation on Structural and Optical Properties of Nanocrystalline Bismuth Ferrite and Manganese Sillenite Powders

2020 ◽  
Vol 835 ◽  
pp. 317-323
Author(s):  
D.A. Rayan ◽  
E.A. Abdel-Mawla ◽  
S.K. Mohamed ◽  
A.A. Mohamed ◽  
Mohamed M. Rashad
Keyword(s):  
Optical Properties ◽  
Bismuth Ferrite ◽  
Ammonium Hydroxide ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Munk Function ◽  
Ft Ir ◽  
Uv Visible ◽  
Co Precipitation

Nanocrystalline bismuth ferrite BFO; BiFeO3 and manganese sillenite, BMO; Bi12MnO20 (BMO) powders have been successfully elaborated using a facile co-precipitation approach. The formed materials were examined using X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM). Furthermore, the change in the optical properties was performed based on Fourier transform infrared spectroscopy (FT-IR) and UV-visible spectrophotometer. Typical, pure BiFeO3 and Bi12MnO20 phases were detected for the precursors precipitated at pH 10 based on ammonium hydroxide as a base then annealed at 500°C for 2h. Eventually, the optical band gap energy of BFO and BMO using Kubelka–Munk function based on Tauc’s plot was found to be 2.12 and 2.79 eV, respectively.

scholarly journals SOLID STATE CHARACTERIZATION OF A NOVEL PHYSICAL INTERACTION (PARACETAMOL-CHLORPHENIRAMINE MALEATE)

2018 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Iyan Sopyan ◽  
Intan Mutiara Sari ◽  
Insan Sunan K.
Keyword(s):  
Solid State ◽  
Pure Substance ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Chlorpheniramine Maleate ◽  
Pharmaceutical Dosage Form ◽  
Pharmaceutical Ingredients ◽  
Ft Ir

Objective: Interactions of active pharmaceutical ingredients (API) as well as pharmaceutical excipients don’t occur in a pharmaceutical dosage form. Base on structures of paracetamol (PCT) and chlorphenamine maleate (CTM), its combination is possible to give a physical interaction in the solid state. This study was conducted to investigate the physical interaction of PCT and CTM in the solid state.Methods: Characterization used the polarization microscope, solubility test, powder x-ray diffraction (PXRD) to observe peak shifting in 2Ɵ angle, and fourier transform infrared spectroscopy (FT-IR) to examine wavenumber shifting.Results: Results of solubility exhibited an increased solubility percentage with increasing concentration. Polarization microscope analysis presented a combination of crystal morphology after the two substances were mixed in an equimolar ratio. The result of melting point determination of each pure substance was 172 °C for PCT, 132 °C for CTM, and 170 °C for the mixture of the two substances in various ratios. Diffractogram showed the shifting at angle 2Ɵ: 20.715, 19.355-23.500 and 21.840, 26.455-20.330 for concentration ratio of PCT: CTM in (132:0.5) and (330:1) respectively and any change in the functional group was observed from infrared spectrum.Conclusion: All evaluation of PCT and CTM in the solid state has exhibited the interaction in solid condition.

Copper (II) Removal by Using Manganese Ferrite in PVA-Alginate Beads

2015 ◽  
Vol 735 ◽  
pp. 177-181
Author(s):  
Ee Ting Wong ◽  
Pei Cheng Teh ◽  
Kian Hwa Chan ◽  
Ani Idris
Keyword(s):  
Sodium Hydroxide Solution ◽  
Alginate Beads ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Drinking Water Standard ◽  
Ft Ir ◽  
Co Precipitation ◽  
Control Study ◽  
Alginate Matrix

The magnetic nanoparticles of manganese-doped magnetite (Mn-Fe2O4) were synthesized by the simple co-precipitation method. The stable Mn2+ and Fe3+ salts in the ratio of 1:2 in aqueous solution, were added into the sodium hydroxide solution to form the Mn-Fe2O4 precipitate at temperature of 95°C. The synthesized nanoparticles were then characterized by Fourier Transform-Infrared Spectroscopy (FT-IR) and X-ray diffraction spectroscopy (XRD). It was then entrapped in the PVA-alginate matrix to form the nanophotoadsorbent in beads form. The synthesized nanoparticles embedded bead was characterized by Scanning Electron Microscopy (SEM). The effects of various parameters, such as contact time, pH, nanoparticles dosage were investigated. The control study was also performed to reveal the performance of photo-adsorbent towards the Cu (II) removal under the light and dark conditions. It was found that the removal efficiency of the Cu (II) achieved 97.07% (1.46ppm) which complied to the WHO drinking water standard of less than 1.5ppm after 180 min treatment.

scholarly journals Synthesis of BaTi5O11 by an aqueous co-precipitation method via stable organic titanate precursor

2021 ◽  
pp. 14-14
Author(s):  
Pelin Aktaş
Keyword(s):  
Aqueous Media ◽  
Average Crystallite Size ◽  
Phase Evolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Ft Ir ◽  
Scherrer Formula ◽  
Co Precipitation

BaTi5O11 has been widely researched due to its unique microwave properties. Conventionally it is challenging to obtain this compound as a single phase. The BaTi5O11 was synthesized via co-precipitation technique using an aqueous solution of titanium(IV)(triethanolaminato) isopropoxide, barium nitrate and ammonia as precursors which are stable in an aqueous media. The phase evolution, purity, and structure were identified by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis. The desired BaTi5O11 structure was obtained by calcination at 900?C. Furthermore, the structure is characterized by TGA, FT-IR and Raman studies. The study showed that the particles were between 80 and 120 nm in size and the average crystallite size was determined from the Scherrer formula as 68.1 nm at 900?C.

Synthesis and Characterization of Structure of Fe3O4@Graphene Oxide Nanocomposites

2016 ◽  
Vol 25 (6) ◽  
pp. 096369351602500 ◽  
Author(s):  
Ruimin Fu ◽  
Mingfu Zhu
Keyword(s):  
Graphene Oxide ◽  
Drug Carrier ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Co Precipitation ◽  
Ft Ir Spectroscopy

Nowadays, the hummers method for preparation of graphene oxide (GO) was improved. The grapheme oxide @ Fe3O4 magnetic nanocomposites were synthesized by co-precipitation method. After analysing the morphology and structure of obtained nanocomposites by X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier transform infrared (FT-IR) spectroscopy, the result was shown as follows. The particle size of Fe3O4 in nanocomposites is 30 nm. Many functional groups are found in grapheme oxide, and such groups could be used to bind with the drug. In the test for magnetic properties, the nanocomposites gathered rapidly in the vicinity of the permanent magnet. The nanocomposites, with high superparamagnetism, can be used in the following applications: drug targeting transports, drug carrier, and diagnosis assistant system.

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