scholarly journals A molecular inclusion complex of atenolol with 2-hydroxypropyl-β-cyclodextrin: The production and characterization thereof

2007 ◽  
Vol 72 (8-9) ◽  
pp. 737-746 ◽  
Author(s):  
Vesna Nikolic ◽  
Ljubisa Nikolic ◽  
Mihajlo Stankovic ◽  
Agnes Kapor ◽  
Mirjana Popsavin ◽  
...  
Keyword(s):  
Inclusion Complex ◽  
1H Nmr ◽  
13C Nmr ◽  
Chemical Shifts ◽  
13C Nmr Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Inclusion ◽  
Ft Ir ◽  
Diffraction Patterns

The molecular inclusion complex of atenolol with 2-hydroxypropyl-?-cyclodextrin was synthesized using the coprecipitation method. The complex obtained was characterized by FT-IR, 1H-NMR, 13C-NMR spectroscopy, as well as by DSC and X-ray diffraction analysis. The DSC analysis confirmed the existence of the complex with the endothermic atenolol melting peak at about 155?C disappearing. The X-ray diffraction patterns of the complex and 2-hydroxypropyl-?-cyclodextrin were very similar, thus confirming the complete inclusion of the atenolol molecule within the cavity of the 2-hydroxypropyl-?-cyclodextrin. The peaks originating from atenolol were completely absent in the diffractogram of the complex. 1H-NMR and 13C-NMR spectra showed certain changes in the chemical shifts of protons and C atoms from atenolol and 2-hydroxypropyl-?-cyclodextrin, indicating that a complex had been formed and also which protons participated in the hydrogen bonds which formed the complex. The atenolol solubility in water was improved (254 mg complex cm-3, i.e., 37.5 mg atenolol cm-3), and in pH 3 HCl solution (251 mg complex cm-3, i.e., 37 mg atenolol cm-3) when compared to pure atenolol, and even when compared to the atenolol complex with ?-cyclodextrin. The increased solubility ensures greater bioavailability of the active component and, due to the low solubility, significantly corrects for the lack of the basic active substance and, simultaneously, increases its overall therapeutic effect, combined with reduced side effects. .

Experimental (13C NMR, 1H NMR, FT-IR, single-crystal X-ray diffraction) and DFT studies on 3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione

2011 ◽  
Vol 83 (1) ◽  
pp. 472-477 ◽  
Author(s):  
Nevin Süleymanoğlu ◽  
Reşat Ustabaş ◽  
Yelda Bingöl Alpaslan ◽  
Fatih Eyduran ◽  
Cengiz Özyürek ◽  
...  
Keyword(s):  
Single Crystal ◽  
1H Nmr ◽  
13C Nmr ◽  
Dft Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

2020 ◽  
Vol 24 (10) ◽  
pp. 1139-1147
Author(s):  
Yang Mingyan ◽  
Wang Daoquan ◽  
Wang Mingan
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
The Other ◽  
Repulsive Interaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Effect ◽  
Group Control

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

scholarly journals Understanding the Performance of a Novel Direct Compression Excipient Comprising Roller Compacted Chitin

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 115 ◽  
Author(s):  
Deeb Abu Fara ◽  
Linda Al-Hmoud ◽  
Iyad Rashid ◽  
Babur Z. Chowdhry ◽  
Adnan Badwan
Keyword(s):  
Ball Milling ◽  
Added Value ◽  
Roller Compaction ◽  
Direct Compression ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Diffraction Patterns ◽  
Hand Drying ◽  
Slight Deformation

Chitin has been investigated in the context of finding new excipients suitable for direct compression, when subjected to roller compaction. Ball milling was concurrently carried out to compare effects from different energy or stress-inducing techniques. Samples of chitin powders (raw, processed, dried and humidified) were compared for variations in morphology, X-ray diffraction patterns, densities, FT-IR, flowability, compressibility and compactibility. Results confirmed the suitability of roller compaction to convert the fluffy powder of raw chitin to a bulky material with improved flow. X-ray powder diffraction studies showed that, in contrast to the high decrease in crystallinity upon ball milling, roller compaction manifested a slight deformation in the crystal lattice. Moreover, the new excipient showed high resistance to compression, due to the high compactibility of the granules formed. This was correlated to the significant extent of plastic deformation compared to the raw and ball milled forms of chitin. On the other hand, drying and humidification of raw and processed materials presented no added value to the compressibility and compactibility of the directly compressed excipient. Finally, compacted chitin showed direct compression similarity with microcrystalline cellulose when formulated with metronidazole (200 mg) without affecting the immediate drug release action of the drug.

scholarly journals Construction of a crossed-layer-structure MoS2/g-C3N4 heterojunction with enhanced photocatalytic performance

RSC Advances ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 6131-6139 ◽  
Author(s):  
Youzhi Cao ◽  
Qiao Li ◽  
Wei Wang
Keyword(s):  
Ir Spectra ◽  
Carbon Nitride ◽  
Photocatalytic Performance ◽  
Layer Structure ◽  
Analytical Techniques ◽  
Graphitic Carbon Nitride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Diffraction Patterns

A novel crossed-layer-structure MoS2/g-C3N4 (graphitic carbon nitride) was synthesized by a facile method, and was characterized by a collection of analytical techniques: X-ray diffraction patterns, FT-IR spectra, SEM, TEM, and XPS.

Synthesis, Characterization, and Catalytic Activity of a Series of Aluminium–Amidate Complexes

2015 ◽  
Vol 68 (3) ◽  
pp. 357 ◽  
Author(s):  
Kevin P. Yeagle ◽  
Darryl Hester ◽  
Nicholas A. Piro ◽  
William G. Dougherty ◽  
W. Scott Kassel ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
X Ray Diffraction ◽  
Metathesis Reaction ◽  
Chloride Complexes ◽  
1H And 13C Nmr ◽  
X Ray

The aluminium complexes {[κ2-N,O-(t-BuNCOPh)]AlMe2}2 (2), [κ2-N,O-(t-BuNCOPh)]2AlMe (3), and [κ2-N,O-(t-BuNCOPh)]3Al (4) were prepared through the protonolysis reaction between trimethylaluminium and one, two, or three equivalents, respectively, of N-tert-butylbenzamide. Complex 2 was also prepared via a salt metathesis reaction between K(t-BuNCOPh) and dimethylaluminium chloride. Complexes 2–4 were characterized using 1H and 13C NMR spectroscopy. Single-crystal X-ray diffraction analysis of the complexes corroborated ligand : metal stoichiometries and revealed that all the amidate ligands coordinate to the aluminium ion in a κ2 fashion. The Al–amidate complexes 2–4 were viable catalyst precursors for the Meerwein–Ponndorf–Verley–Oppenauer reduction–oxidation manifold, successfully interconverting several classes of carbonyl and alcohol substrates.

Thiophene ring-opening reactions IV. Facile generation of novel ethyl 4-hydroxy-6-thioxonicotinate─1,3,4- thiadiazoline hybrids

2021 ◽  
Vol 18 ◽  
Author(s):  
Mohammed M. Abadleh ◽  
Ahmad H. Abdullah ◽  
Jalal A. Zahra ◽  
Salim S. Sabri ◽  
Firas F. Awwadi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectral Data ◽  
1H Nmr ◽  
13C Nmr ◽  
Ring Opening ◽  
Thiophene Ring ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Ring Opening Reactions

: A set of triethylammonium 4-oxo-6-pyridinethiolate–1,3,4-thiadiazoline hybrids (3a-e) were prepared via the reaction of ethyl 2-chloro-6-cyclopropyl-3- nitro-4-oxothieno[2,3-b]pyridine- 5-carboxylate (2) with the appropriate thiobenzoyl- hydrazide (1a-e) in acetonitrile and triethylamine. These hybrids were readily converted, under neutral mild conditions, into the corresponding 4-hydroxy-6-thioxopyridine –thiadiazoline hybrids (5a-e). The structures of the latter set are supported by HRMS, 1H NMR and 13C NMR spectral data and further confirmed by single-crystal X-ray diffraction studies. Alkylation of these hybrids in the presence of triethylamine occurred exclusively at the 6-thioxosulfur, yielding the respective 6-sulfanyl derivatives (6a-c).

scholarly journals Synthesis and structure of 1-benzyl-5-amino-1H-tetrazole in the solid state and in solution: Combining X-ray diffraction, 1H NMR, FT–IR, and UV–Vis spectra and DFT calculations

2015 ◽  
Vol 18 (4) ◽  
pp. 422-429 ◽  
Author(s):  
Ayyaz Mahmood ◽  
Islam Ullah Khan ◽  
Ricardo L. Longo ◽  
Ahmad Irfan ◽  
Sohail Anjum Shahzad
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
1H Nmr ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

scholarly journals Reciprocal Powered Time model for Release Kinetic Analysis of Ibuprofen Solid Dispersions in Oleaster Powder, Microcrystalline Cellulose and Crospovidone

2010 ◽  
Vol 13 (2) ◽  
pp. 152 ◽  
Author(s):  
Ghobad Mohammadi ◽  
Mohammad Barzegar-Jalali ◽  
Hadi Valizadeh ◽  
Hossein Nazemiyeh ◽  
Azim Barzegar-Jalali ◽  
...  
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Solid Dispersions ◽  
Release Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Diffraction Patterns ◽  
Release Data ◽  
Dsc Thermograms

ABSTRACT- Purpose. A physically sound derivation for reciprocal power time (RPT) model for kinetic of drug release is given. In order to enhance ibuprofen dissolution, its solid dispersions (SDs) prepared by cogrinding technique using crospovidone (CP), microcrystalline cellulose (MC) and oleaster powder (OP) as a novel carrier and the model applied to the drug release data. Methods. The drug cogrounds with the carriers were prepared and subjected to the dissolution studies. For elucidation of observed in vitro differences, FT-IR spectroscopy, X-ray diffraction patterns, DSC thermograms and laser particle size measurement were conducted. Results. All drug release data fitted very well to newly derived RPT model. The efficiency of the carriers for dissolution enhancement was in the order of: CP>OP>MC. The corresponding release kinetic parameter derived from the model, t50% (time required for 50% dissolution) for the carrier to drug ratio 2:1 were 2.7, 10.2 and 12.6 min, respectively. The efficiency of novel carrier, OP, was between CP and MC. FT-IR showed no interaction between the carriers and drug. The DSC thermograms and X-ray diffraction patterns revealed a slight reduced crystallinty in the SDs. Also grinding reduced mean particle size of drug from 150.7 to 44.4 µm. Conclusion. An improved derivation for RPT model was provided which the parameter of the model, t50%, unlike to previous derivations was related to the most important property of the drug i.e. its solubility. The model described very well drug release kinetics from the solid dispersions. Cogrinding was an effective technique in enhancing dissolution rate of ibuprofen. Elaeagnus angostifolia fruit powder was suggested as a novel potential hydrophilic carrier in preparing solid dispersion of ibuprofen.

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