scholarly journals Inclusion Complex of Plai Oil and β-Cyclodextrin

2016 ◽  
Vol 855 ◽  
pp. 47-53
Author(s):  
Ampa Jimtaisong ◽  
Nisakorn Saewan
Keyword(s):  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Physicochemical Characteristic ◽  
Precipitation Method ◽  
Ir Absorption ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Complex Preparation ◽  
Ft Ir ◽  
Co Precipitation

Inclusion complex of β-cyclodextrin (β-CD) and Plai (Zingiber cassumunar) oil was prepared using a simple co-precipitation method at β-CD to Plai oil in different ratios. The inclusion complexes were characterized using Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The FT-IR absorption bands of inclusion complex at 3600-3200 cm-1 were broader and shifted toward lower frequencies compared with that of pure β-CD (3359 cm-1). DSC of the inclusion complexes showed two endothermic peaks shifted to lower temperatures (90-100°C and 295-300°C) compared to that of β-CD. The different physicochemical characteristic could be an indication of an embedded guest molecule in the β-CD cavities in the inclusion complex preparation.

scholarly journals Preparation, Characterization, and Acetylcholinesterase Inhibitory Ability of the Inclusion Complex of β-Cyclodextrin–Cedar (Juniperus phoenicea) Essential Oil

Micro ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 250-266
Author(s):  
Eleni Kavetsou ◽  
Ioanna Pitterou ◽  
Annita Katopodi ◽  
Georgia Petridou ◽  
Abdelaziz Adjali ◽  
...  
Keyword(s):  
Essential Oil ◽  
In Vitro Release ◽  
Release Profile ◽  
Acetylcholinesterase Inhibition ◽  
Precipitation Method ◽  
Scanning Calorimetry ◽  
Juniperus Phoenicea ◽  
Ft Ir ◽  
Co Precipitation

The aim of the present study was the encapsulation of cedar (Juniperus phoenicea) essential oil (CEO) of Greek origin in β-cyclodextrin (β-CD) through the formation of inclusion complexes (ICs) using the co-precipitation method with different β-CD-to-CEO weight ratios (90:10, 85:15, 80:20, 70:30 (w/w)). The encapsulation of CEO in β-CD through host–guest interactions was confirmed by Nuclear Magnetic Resonance (NMR) spectroscopy, FT-IR spectroscopy, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The obtained ICs exhibited nanoscale size (315.9 nm to 769.6 nm),Polydispersity Index from 0.326 to 0.604 and satisfactory stability in suspension (−37.0 mV to −17.0 mV). The process yield was satisfactory, ranging between 65% and 78%, while the inclusion efficiency ranged from 10% to 27%. The in vitro release study conducted for the IC with the optimal characteristics (β-CD:CEO 80:20 (w/w)) exhibited a sustained release profile, with an initial burst effect in the first 5 h. The release profile could be well expressed by the Higuchi equation: Q = 18.893 t1/2 + 9.5919, R2 = 0.8491. The cedar EO presented significant acetylcholinesterase inhibition (IC50 37 μg/mL), which was prolonged by its encapsulation into the β-CD cavity.

scholarly journals Preparation and characterization of artemether inclusion complexes with hydroxypropyl-β-cyclodextrin

2017 ◽  
Vol 16 (10) ◽  
pp. 2359-2364
Author(s):  
Zwanden Sule Yahaya ◽  
Kenneth C. Ofokansi ◽  
Suzane T. Allagh ◽  
Pat G. Bhatia
Keyword(s):  
Complex Formation ◽  
Inclusion Complex ◽  
Dissolution Rate ◽  
Inclusion Complexes ◽  
In Vitro Dissolution ◽  
Phase Solubility ◽  
Inclusion Complex Formation ◽  
Scanning Calorimetry ◽  
Ft Ir

Purpose: To investigate experimentally the inclusion of artemether into the cavity of  hydroxypropyl-β-cyclodextrin and examine its effect on the solubility and dissolution rate of the drug.Methods: Inclusion complexes of artemether with hydroxypropyl-β-cyclodextrin of molar ratios 1:1, 1:2 and 1:3 were prepared using the kneading method. Phase solubility analysis and in vitro dissolution studies were utilized in evaluating the influence of inclusion complex formation on the solubility and dissolution rate of the drug. The complexes were characterized using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The inclusion complex containing equimolar concentrations of artemether and hydroxypropyl-β-cyclodextrin was then formulated into tablets via direct compression and  evaluated for various pharmaceutical characteristics including hardness, friability, absolute drug content and comparative in vitro dissolution profiles with some  commercially available brands of artemether.Results: The phase solubility diagram for the formed complexes in water at 37 oC indicated a linear curve soluble complex system (referred to as the AL system), and a stability constant (KC) value of 143 M-1. Evidence consistent with inclusion complex formation was obtained using FT-IR and DSC. The formulated inclusion complex tablets exhibited a higher rate of dissolution than the pure drug and commercial brands, showing 3.9-, 1.8- and 1.6-fold increases, respectively, over a period of 15 min.Conclusion: Inclusion complexation of artemether with hydroxypropyl-β-cyclodextrin is a promising approach to enhance the solubility and dissolution rate of the drug.Keywords: Artemether, 2-Hydroxypropyl-β-cyclodextrin, Dissolution, Solubility enhancement, Inclusion complex

scholarly journals Novel β-Cyclodextrin and Catnip Essential Oil Inclusion Complex and Its Tick Repellent Properties

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7391
Author(s):  
Jennifer Hogenbom ◽  
Mouaz Istanbouli ◽  
Nicoletta Faraone
Keyword(s):  
Essential Oil ◽  
Inclusion Complex ◽  
Physicochemical Properties ◽  
Blood Feeding ◽  
Qualitative Assessment ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Nepeta Cataria ◽  
Ft Ir ◽  
Co Precipitation

Cyclodextrin inclusion complexes have been successfully used to encapsulate essential oils, improving their physicochemical properties and pharmacological effects. Besides being well-known for its effects on cats and other felines, catnip (Nepeta cataria) essential oil demonstrates repellency against blood-feeding pests such as mosquitoes. This study evaluates the tick repellency of catnip oil alone and encapsulated in β-cyclodextrin, prepared using the co-precipitation method at a 1:1 molar ratio. The physicochemical properties of this inclusion complex were characterized using GC-FID for encapsulation efficiency and yield and SPME/GC-MS for volatile emission. Qualitative assessment of complex formation was done by UV-Vis, FT-IR, 1H NMR, and SEM analyses. Catnip oil at 5% (v/v) demonstrated significant tick repellency over time, being comparable to DEET as used in commercial products. The prepared [catnip: β-CD] inclusion complex exerted significant tick repellency at lower concentration of the essential oil (equivalent of 1% v/v). The inclusion complex showed that the release of the active ingredient was consistent after 6 h, which could improve the effective repellent duration. These results demonstrated the effective tick repellent activity of catnip essential oil and the successful synthesis of the inclusion complex, suggesting that β-CDs are promising carriers to improve catnip oil properties and to expand its use in repellent formulations for tick management.

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.

Nevirapine Pharmaceutical Cocrystal: Design, Development and Formulation

2019 ◽  
Vol 9 (3) ◽  
pp. 240-247
Author(s):  
Prabhakar Panzade ◽  
Priyanka Somani ◽  
Pavan Rathi
Keyword(s):  
Dosage Form ◽  
In Vitro Dissolution ◽  
Soluble Form ◽  
Ir Absorption ◽  
Stoichiometric Ratio ◽  
Design Development ◽  
Formulation Development ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Pharmaceutical Cocrystal

Background and Objective: The top approach to deliver poorly soluble drugs is the use of a highly soluble form. The present study was conducted to enhance the solubility and dissolution of a poorly aqueous soluble drug nevirapine via a pharmaceutical cocrystal. Another objective of the study was to check the potential of the nevirapine cocrystal in the dosage form. Methods: A neat and liquid assisted grinding method was employed to prepare nevirapine cocrystals in a 1:1 and 1:2 stoichiometric ratio of drug:coformer by screening various coformers. The prepared cocrystals were preliminary investigated for melting point and saturation solubility. The selected cocrystal was further confirmed by Infrared Spectroscopy (IR), Differential Scanning Calorimetry (DSC), and Xray Powder Diffraction (XRPD). Further, the cocrystal was subjected to in vitro dissolution study and formulation development. Results: The cocrystal of Nevirapine (NVP) with Para-Amino Benzoic Acid (PABA) coformer prepared by neat grinding in 1:2 ratio exhibited greater solubility. The shifts in IR absorption bands, alterations in DSC thermogram, and distinct XRPD pattern showed the formation of the NVP-PABA cocrystal. Dissolution of NVP-PABA cocrystal enhanced by 38% in 0.1N HCl. Immediate release tablets of NVP-PABA cocrystal exhibited better drug release and less disintegration time. Conclusion: A remarkable increase in the solubility and dissolution of NVP was obtained through the cocrystal with PABA. The cocrystal also showed great potential in the dosage form which may provide future direction for other drugs.

scholarly journals Phase Transition and Coefficients of Thermal Expansion in Al2−xInxW3O12 (0.2 ≤ x ≤ 1)

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4021
Author(s):  
Andrés Esteban Cerón Cerón Cortés ◽  
Anja Dosen ◽  
Victoria L. Blair ◽  
Michel B. Johnson ◽  
Mary Anne White ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Expansion ◽  
Thermal Shock ◽  
Monoclinic Phase ◽  
Ceramic Materials ◽  
Precipitation Method ◽  
Scanning Calorimetry ◽  
Orthorhombic Crystal ◽  
Co Precipitation

Materials from theA2M3O12 family are known for their extensive chemical versatility while preserving the polyhedral-corner-shared orthorhombic crystal system, as well as for their consequent unusual thermal expansion, varying from negative and near-zero to slightly positive. The rarest are near-zero thermal expansion materials, which are of paramount importance in thermal shock resistance applications. Ceramic materials with chemistry Al2−xInxW3O12 (x = 0.2–1.0) were synthesized using a modified reverse-strike co-precipitation method and prepared into solid specimens using traditional ceramic sintering. The resulting materials were characterized by X-ray powder diffraction (ambient and in situ high temperatures), differential scanning calorimetry and dilatometry to delineate thermal expansion, phase transitions and crystal structures. It was found that the x = 0.2 composition had the lowest thermal expansion, 1.88 × 10−6 K−1, which was still higher than the end member Al2W3O12 for the chemical series. Furthermore, the AlInW3O12 was monoclinic phase at room temperature and transformed to the orthorhombic form at ca. 200 °C, in contrast with previous reports. Interestingly, the x = 0.2, x = 0.4 and x = 0.7 materials did not exhibit the expected orthorhombic-to-monoclinic phase transition as observed for the other compositions, and hence did not follow the expected Vegard-like relationship associated with the electronegativity rule. Overall, compositions within the Al2−xInxW3O12 family should not be considered candidates for high thermal shock applications that would require near-zero thermal expansion properties.

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

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.

scholarly journals Effect of La2O3 as a Promoter on the Pt,Pd,Ni/MgO Catalyst in Dry Reforming of Methane Reaction

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 750 ◽  
Author(s):  
Ali M. A. Al-Najar ◽  
Faris A. J. Al-Doghachi ◽  
Ali A. A. Al-Riyahee ◽  
Yun Hin Taufiq-Yap
Keyword(s):  
Carbon Deposition ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
Bet Method ◽  
Spent Catalysts ◽  
Ft Ir ◽  
Co Precipitation ◽  
Surfactant Assisted

Pt,Pd,Ni/MgO, Pt,Pd,Ni/Mg0.97La3+0.03O, Pt,Pd,Ni/Mg0.93La3+0.07O, and Pt,Pd,Ni/Mg0.85La3+0.15O (1% of each of the Ni, Pd, and Pt) catalysts were prepared by a surfactant-assisted co-precipitation method. Samples were characterized by the XRD, XPS, XRF, FT-IR, H2-TPR, TEM, the Brunauer–Emmett–Teller (BET) method, and TGA and were tested for the dry reforming of methane (DRM). TEM and thermal gravimetric analysis (TGA) methods were used to analyze the carbon deposition on spent catalysts after 200 h at 900 °C. At a temperature of 900 °C and a 1:1 CH4:CO2 ratio, the tri-metallic Pt,Pd,Ni/Mg0.85La3+0.15O catalyst with a lanthanum promoter showed a higher conversion of CH4 (85.01%) and CO2 (98.97%) compared to the Ni,Pd,Pt/MgO catalysts in the whole temperature range. The selectivity of H2/CO decreased in the following order: Pt,Pd,Ni/Mg0.85La3+0.15O > Pt,Pd,Ni/Mg0.93La3+0.07O > Pt,Pd,Ni/Mg0.97La3+0.03O > Ni,Pd,Pt/MgO. The results indicated that among the catalysts, the Pt,Pd,Ni/Mg0.85La23+0.15O catalyst exhibited the highest activity, making it the most suitable for the dry reforming of methane reaction.

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

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