scholarly journals Vibrational Spectroscopy for Cocrystals Screening. A Comparative Study

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3263 ◽  
Author(s):  
Marisa Rodrigues ◽  
João Lopes ◽  
Mafalda Sarraguça
Keyword(s):  
Vibrational Spectroscopy ◽  
Near Infrared ◽  
Screening Method ◽  
Growing Up ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Drug Products ◽  
Infrared And Raman Spectroscopy ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

A recurrent problem faced by the pharmaceutical industry when formulating drug products concerns poorly soluble drugs, which, despite having desirable pharmacological activity, present limited bioavailability. Cocrystallization is growing up as a possible approach to tackle this problem. Cocrystals are crystalline materials comprising at least two components, solid at room temperature, and held together by non-covalent bonds. The increasing interest in these compounds is steadily demanding faster, simpler, and more reliable methods for the task of screening new cocrystals. This work aims at comparing the performance of three vibrational spectroscopy techniques (mid infrared, near infrared, and Raman spectroscopy) for cocrystals screening. Presented results are based on hydrochlorothiazide, a poorly soluble drug belonging to class IV of the Biopharmaceutical Classification System. The implemented cocrystal screening procedure tested six coformers (all considered safe for human administration) added according to a drug:coformer ratio of 1:1 and 1:2 and seven solvents with different polarity. The screening method chosen was based on slurry cocrystallization performed by sonication (ultrasound assisted) in a 96-well plate. Results show that all evaluated vibrational spectroscopy techniques provided important information regarding cocrystal formation, including information on the groups involved in the cocrystallization and purity, and can be used for the screening task.

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

2017 ◽  
Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  
Keyword(s):  
Molecular Transport ◽  
Controlled Synthesis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
Seeded Growth ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Step Procedure ◽  
Structures And Properties ◽  
2D Polymer

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

2017 ◽  
Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  
Keyword(s):  
Molecular Transport ◽  
Controlled Synthesis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
Seeded Growth ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Step Procedure ◽  
Structures And Properties ◽  
2D Polymer

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

Impact of Drug-Polymer Interaction in Amorphous Solid Dispersion Aiming for the Supersaturation of Poorly Soluble Drug in Biorelevant Medium

2020 ◽  
Vol 21 (5) ◽  
Author(s):  
Cassiana Mendes ◽  
Rafael G. Andrzejewski ◽  
Juliana M. O. Pinto ◽  
Leice M. R. de Novais ◽  
Andersson Barison ◽  
...  
Keyword(s):  
Solid Dispersion ◽  
Amorphous Solid ◽  
Amorphous Solid Dispersion ◽  
Poorly Soluble ◽  
Poorly Soluble Drug ◽  
Drug Polymer Interaction ◽  
Biorelevant Medium ◽  
Polymer Interaction

scholarly journals Applications of Vibrational Spectroscopy for Analysis of Connective Tissues

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 922
Author(s):  
William Querido ◽  
Shital Kandel ◽  
Nancy Pleshko
Keyword(s):  
Raman Spectroscopy ◽  
Vibrational Spectroscopy ◽  
Near Infrared ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Label Free ◽  
Connective Tissues ◽  
Bone Properties ◽  
Composition And Structure

Advances in vibrational spectroscopy have propelled new insights into the molecular composition and structure of biological tissues. In this review, we discuss common modalities and techniques of vibrational spectroscopy, and present key examples to illustrate how they have been applied to enrich the assessment of connective tissues. In particular, we focus on applications of Fourier transform infrared (FTIR), near infrared (NIR) and Raman spectroscopy to assess cartilage and bone properties. We present strengths and limitations of each approach and discuss how the combination of spectrometers with microscopes (hyperspectral imaging) and fiber optic probes have greatly advanced their biomedical applications. We show how these modalities may be used to evaluate virtually any type of sample (ex vivo, in situ or in vivo) and how “spectral fingerprints” can be interpreted to quantify outcomes related to tissue composition and quality. We highlight the unparalleled advantage of vibrational spectroscopy as a label-free and often nondestructive approach to assess properties of the extracellular matrix (ECM) associated with normal, developing, aging, pathological and treated tissues. We believe this review will assist readers not only in better understanding applications of FTIR, NIR and Raman spectroscopy, but also in implementing these approaches for their own research projects.

Small-Angle X-Ray Scattering and Near-Infrared Vibrational Spectroscopy of Water Confined in Aerosol-OT Reverse Micelles

ChemPhysChem ◽  
2008 ◽  
Vol 9 (18) ◽  
pp. 2794-2801 ◽  
Author(s):  
Sangeetha Balakrishnan ◽  
Nadeem Javid ◽  
Hermann Weingärtner ◽  
Roland Winter
Keyword(s):  
Vibrational Spectroscopy ◽  
Small Angle ◽  
Reverse Micelles ◽  
Near Infrared ◽  
X Ray ◽  
Aerosol Ot ◽  
X Ray Scattering ◽  
Ray Scattering

Multicomponent Amorphous Nanofibers Electrospun from Hot Aqueous Solutions of a Poorly Soluble Drug

2010 ◽  
Vol 27 (11) ◽  
pp. 2466-2477 ◽  
Author(s):  
Deng-Guang Yu ◽  
Li-Dong Gao ◽  
Kenneth White ◽  
Christopher Branford-White ◽  
Wei-Yue Lu ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

In vitro models to evaluate the permeability of poorly soluble drug entities: Challenges and perspectives

2012 ◽  
Vol 45 (3) ◽  
pp. 235-250 ◽  
Author(s):  
Stephen T. Buckley ◽  
Sarah M. Fischer ◽  
Gert Fricker ◽  
Martin Brandl
Keyword(s):  
In Vitro Models ◽  
Poorly Soluble ◽  
Poorly Soluble Drug
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