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Biotechnology Letters Apr 2020The yeast cells were coated with FeO magnetic nanoparticles and employed as biocatalyst for the microbial biotransformation of benzaldehyde into L-phenylacetylcarbinol...
OBJECTIVES
The yeast cells were coated with FeO magnetic nanoparticles and employed as biocatalyst for the microbial biotransformation of benzaldehyde into L-phenylacetylcarbinol (L-PAC).
RESULTS
Saccharomyces cerevisiae CEN.PK113-7D yeast cells were coated with magnetic nanoparticles to facilitate the cells separation process. Transmission electron microscopy, powder XRD diffraction, and vibrating sample magnetometer were used to characterize magnetic nanoparticles and magnetic nanoparticle-coated yeast cells. Then the reusability of magnetically recoverable cells in production of L-PAC was investigated. Results show that coating yeast cells with magnetic nanoparticles does not affect their size and structure. Coated cells were also used in seven consecutive batch cycles and no significant reduction for L-PAC titer was observed in any of the cycles.
CONCLUSION
Coating yeast cells with magnetic nanoparticles enabled rapid separation and reuse of cells in several successive batch cycle without affecting their ability to produce L-PAC.
Topics: Acetone; Batch Cell Culture Techniques; Benzaldehydes; Biocatalysis; Biotransformation; Magnetite Nanoparticles; Microscopy, Electron, Transmission; Particle Size; Powder Diffraction; Saccharomyces cerevisiae; X-Ray Diffraction
PubMed: 31950407
DOI: 10.1007/s10529-020-02798-0 -
Molecular Pharmaceutics Apr 2021In this study, various structurally similar aliphatic dicarboxylic acids, namely, succinic acid, glutaric acid, adipic acid, and pimelic acid, were employed as coformers...
In this study, various structurally similar aliphatic dicarboxylic acids, namely, succinic acid, glutaric acid, adipic acid, and pimelic acid, were employed as coformers to obtain phase pure cocrystals with berberine chloride (BCl) by a slow solvent evaporation method. The structures of the four novel salt-cocrystals of BCl were determined by single crystal X-ray diffraction analysis and their solid-state properties were characterized. Compared with BCl·2HO, all the cocrystals showed a higher melting point, improved powder dissolution and intrinsic dissolution rate (IDR), and lower hygroscopicity. It is noteworthy that the melting points and IDRs of these cocrystals exhibit an odd-even alternation with the carbon chain length of the acids.
Topics: Administration, Oral; Berberine; Biological Availability; Calorimetry, Differential Scanning; Chemistry, Pharmaceutical; Dicarboxylic Acids; Drug Compounding; Drug Liberation; Excipients; Hydrogen Bonding; Powder Diffraction; Solubility
PubMed: 33656348
DOI: 10.1021/acs.molpharmaceut.0c01250 -
Environmental Geochemistry and Health Aug 2018Clays and muds have been used for centuries as cosmetics or pharmaceutical products for various therapies. The suitability of muds and clays for health- and...
Clays and muds have been used for centuries as cosmetics or pharmaceutical products for various therapies. The suitability of muds and clays for health- and beauty-related applications depends on their physicochemical properties, mineralogical composition, particle characteristics and toxicity. In this work, the physicochemical characterization of 12 mud specimens from different natural spa resorts in Greece and one from Israel (Dead Sea) is presented. All specimens were sterilized at 121 °C for 20 min, because of their intended use. The Greek mud specimens were collected from various locations in Macedonia, Western Greece and Northeast Aegean. All muds were characterized concerning their mineralogical, chemical components as well as their morphological characteristics using appropriate methods [powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), nitrogen absorption specific surface area measurements (BET), scanning electron microscopy and energy dispersive X-ray spectroscopy]. The concentrations of F, Cl, NO and SO anions at equilibrium with the mud specimens were measured by ion chromatography. Total calcium concentration was measured using atomic absorption spectroscopy, and the concentration of total N, C, H and S in the solids was measured using elemental analysis. Moreover, total phenolic concentration (TPC) in distilled water equilibrated with the mud specimens was measured as an index for their antioxidant properties. Several muds were found to present high TPC. Several of the examined mud specimens were found to have the potential use as pharmaceuticals or cosmetics. Based on the physicochemical characteristics of the mud specimens examined, possible improvement in their use and applicability has been suggested.
Topics: Aluminum Silicates; Anions; Antioxidants; Calcium; Clay; Cosmetics; Greece; Israel; Microscopy, Electron, Scanning; Organic Chemicals; Pharmaceutical Preparations; Phenols; Powder Diffraction; Spectrometry, X-Ray Emission; Spectrophotometry, Atomic; Sterilization; Thermogravimetry
PubMed: 29290013
DOI: 10.1007/s10653-017-0066-8 -
Journal of Pharmaceutical Sciences Nov 2018The aim of this study was to investigate if mechanistically different controlled ice nucleation techniques in freeze-drying are comparable to each other with respect to... (Comparative Study)
Comparative Study
The aim of this study was to investigate if mechanistically different controlled ice nucleation techniques in freeze-drying are comparable to each other with respect to drying process performance and product quality attributes. Therefore, we studied 3 different model formulations including amorphous (sucrose, trehalose) and semi-crystalline (mannitol:sucrose 4:1) solids containing a monoclonal antibody IgG (5 g/L) processed either by application of ice fog or depressurization technique setting an ice nucleation temperature of -5°C. Subsequently, the same freeze-drying protocol on identical machinery was applied. The results showed that the techniques are comparable with respect to the thermal history of product temperature sensors and primary drying time, solid state- and protein-related product quality attributes. All analytics comprising Karl Fischer titration, X-ray powder diffraction and Brunauer-Emmet-Teller as well as high-performance size exclusion chromatography, turbidity and subvisible particle counting using flow-imaging microscopy exhibited similarity and comparability among the controlled nucleation protocols.
Topics: Antibodies, Monoclonal; Drug Compounding; Excipients; Freeze Drying; Ice; Immunoglobulin G; Mannitol; Powder Diffraction; Protein Aggregates; Sucrose; Trehalose; X-Ray Diffraction
PubMed: 30055225
DOI: 10.1016/j.xphs.2018.07.019 -
European Journal of Pharmaceutics and... Jan 2019Drug-amino acid co-amorphous systems have become increasingly well-investigated systems to improve dissolution rate of poorly water-soluble drugs. In this study,...
Drug-amino acid co-amorphous systems have become increasingly well-investigated systems to improve dissolution rate of poorly water-soluble drugs. In this study, dipeptides were investigated as co-formers for co-amorphous systems based on the hypothesis that dipeptides might combine the inherent properties of the two included amino acids. Co-amorphization of the model drug mebendazole was investigated with five dipeptides, tryptophan-phenylalanine, phenylalanine-tryptophan, aspartic acid-tyrosine, histidine-glycine and proline-tryptophan. The dipeptides were chosen to investigate whether the side chains (nonpolar, polar, basic and acidic), and the sequence of amino acids (tryptophan-phenylalanine versus phenylalanine-tryptophan) have an influence on the performance of dipeptides as co-formers. All mebendazole-dipeptide systems became amorphous after ball milling for only 30 min, while this generally was not the case for the single amino acids or physical mixtures of the amino acids forming the dipeptides. Dissolution studies showed that the dissolution rate of mebendazole from most co-amorphous systems was increased significantly compared to crystalline and amorphous mebendazole. However, no clear trend for the drug dissolution enhancement was observed within the different co-amorphous drug-dipeptide systems. The stability study revealed that co-amorphous mebendazole-dipeptide systems showed higher physical stability compared to amorphous mebendazole. In conclusion, dipeptides are shown to be promising co-formers for co-amorphous systems.
Topics: Calorimetry, Differential Scanning; Chemistry, Pharmaceutical; Dipeptides; Drug Compounding; Drug Liberation; Drug Stability; Excipients; Mebendazole; Powder Diffraction; X-Ray Diffraction
PubMed: 30468836
DOI: 10.1016/j.ejpb.2018.11.016 -
Journal of Pharmaceutical Sciences May 2015The focus of present investigation was to explore X-ray powder diffraction (XRPD) and solid-state nuclear magnetic resonance (ssNMR) techniques for amorphous and... (Comparative Study)
Comparative Study
Comparison of X-ray powder diffraction and solid-state nuclear magnetic resonance in estimating crystalline fraction of tacrolimus in sustained-release amorphous solid dispersion and development of discriminating dissolution method.
The focus of present investigation was to explore X-ray powder diffraction (XRPD) and solid-state nuclear magnetic resonance (ssNMR) techniques for amorphous and crystalline tacrolimus quantification in the sustained-release amorphous solid dispersion (ASD), and to propose discriminating dissolution method that can detect crystalline drug. The ASD and crystalline physical mixture was mixed in various proportions to make sample matrices containing 0%-100% crystalline-amorphous tacrolimus. Partial-least-square regression and principle component regression were applied to the spectral data. Dissolution of the ASD in the US FDA recommended dissolution medium with and without surfactant was performed. R(2) > 0.99 and slope was close to one for all the models. Root-mean-square of prediction, standard error of prediction, and bias were higher in ssNMR-based models when compared with XRPD data models. Dissolution of the ASD decreased with an increase in the crystalline tacrolimus in the formulations. Furthermore, detection of crystalline tacrolimus in the ASD was progressively masked with an increase in the surfactant level in the dissolution medium. XRPD and ssNMR can be used equally to quantitate the crystalline and amorphous fraction of tacrolimus in the ASD with good accuracy; however, ssNMR data collection time is excessively long, and minimum surfactant level in the dissolution medium maximizes detection of crystalline reversion in the formulation.
Topics: Crystallization; Delayed-Action Preparations; Magnetic Resonance Spectroscopy; Powder Diffraction; Solubility; Tacrolimus; X-Ray Diffraction
PubMed: 25753829
DOI: 10.1002/jps.24400 -
Acta Crystallographica. Section A,... May 2021Advances in instrumentation, as well as the development of powerful crystallographic software have significantly facilitated the collection of high-resolution...
Advances in instrumentation, as well as the development of powerful crystallographic software have significantly facilitated the collection of high-resolution diffraction data and have made X-ray powder diffraction (XRPD) particularly useful for the extraction of structural information; this is true even for complex molecules, especially when combined with synchrotron radiation. In this study, in-line with past instrumental profile studies, an improved data collection strategy exploiting the MYTHEN II detector system together with significant beam focusing and tailored data collection options was introduced and optimized for protein samples at the Material Science beamline at the Swiss Light Source. Polycrystalline precipitates of octreotide, a somatostatin analog of particular pharmaceutical interest, were examined with this novel approach. XRPD experiments resulted in high angular and d-spacing (1.87 Å) resolution data, from which electron-density maps of enhanced quality were extracted, revealing the molecule's structural properties. Since microcrystalline precipitates represent a viable alternative for administration of therapeutic macromolecules, XRPD has been acknowledged as the most applicable tool for examining a wide spectrum of physicochemical properties of such materials and performing studies ranging from phase identification to complete structural characterization.
Topics: Crystallography, X-Ray; Macromolecular Substances; Octreotide; Photons; Powder Diffraction
PubMed: 33944797
DOI: 10.1107/S2053273321001698 -
Pharmaceutical Development and... Nov 2016Carvedilol is an antihypertensive drug with non-selective blockade (moderate selectivity for β1 and β2 adrenoceptors) and vasodilating properties due to α receptor...
Carvedilol is an antihypertensive drug with non-selective blockade (moderate selectivity for β1 and β2 adrenoceptors) and vasodilating properties due to α receptor blockade. Its molecule has one chiral centre; therefore, the drug has two enantiomers. Furthermore, it presents different polymorphs depending on the synthesis route and crystallization procedure. Carvedilol is a weak base that is substantially insoluble in water, acidic solutions, and gastric and intestinal fluids; it is classified as a Class II drug in the Biopharmaceutical Classification System. The solubility of carvedilol varies according to the solvent pH. This study aimed to evaluate and correlate the physicochemical and processability properties of carvedilol. Samples of the active ingredient from three different manufacturers were characterized according to their flowability, particle size and apparent density and using microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, intrinsic dissolution and powder dissolution tests. It was determined that the tested samples presented the same polymorphic form, did not present good flowability, and presented different particle size distributions. The tests to evaluate flowability and compressibility were shown to be discriminative, and slight differences among the samples were noted.
Topics: Calorimetry, Differential Scanning; Carbazoles; Carvedilol; Chemistry, Pharmaceutical; Crystallization; Microscopy, Electron, Scanning; Particle Size; Powder Diffraction; Powders; Propanolamines; Solubility; Solvents; Spectroscopy, Fourier Transform Infrared; Technology, Pharmaceutical; X-Ray Diffraction
PubMed: 26336079
DOI: 10.3109/10837450.2015.1073740 -
Molecules (Basel, Switzerland) May 2021This study aimed to design an effective nanoparticle-based carrier for the oral delivery of fisetin (FST) with improved biopharmaceutical properties. FST-loaded...
This study aimed to design an effective nanoparticle-based carrier for the oral delivery of fisetin (FST) with improved biopharmaceutical properties. FST-loaded nanoparticles were prepared with polyvinyl alcohol (PVA) and poly(lactic-co-glycolic acid) (PLGA) by the interfacial deposition method. A central composite design of two independent variables, the concentration of PVA and the amount of PLGA, was applied for the optimization of the preparative parameter. The responses, including average particle size, polydispersity index, encapsulation efficiency, and zeta potential, were assessed. The optimized formulation possessed a mean particle size of 187.9 nm, the polydispersity index of 0.121, encapsulation efficiency of 79.3%, and zeta potential of -29.2 mV. The morphological observation demonstrated a globular shape for particles. Differential scanning calorimetry and powder X-ray diffraction studies confirmed that the encapsulated FST was presented as the amorphous state. The dissolution test indicated a 3.06-fold increase for the accumulating concentrations, and the everted gut sac test showed a 4.9-fold gain for permeability at the duodenum region. In conclusion, the optimized FST-loaded nanoparticle formulation in this work can be developed as an efficient oral delivery system of FST to improve its biopharmaceutic properties.
Topics: Calorimetry, Differential Scanning; Chromatography, High Pressure Liquid; Drug Compounding; Drug Design; Flavonols; Hydrogen-Ion Concentration; Intestinal Mucosa; Nanotechnology; Particle Size; Powder Diffraction; Reproducibility of Results; Spectrum Analysis
PubMed: 34069585
DOI: 10.3390/molecules26103031 -
Spectrochimica Acta. Part A, Molecular... Mar 2015Silver nanoparticles have been synthesized by a simple and inexpensive solution combustion method with urea as fuel. The structural and morphology of the silver...
Silver nanoparticles have been synthesized by a simple and inexpensive solution combustion method with urea as fuel. The structural and morphology of the silver nanoparticles were investigated through X-ray powder diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersion Spectra (EDS) techniques. Structural and morphological results confirmed the nanocrystalline nature of the silver nanoparticles. Density Functional Theory (DFT) calculations were also performed to study the ground and excited state behavior of 2-bromo-1,4-naphthoquinone (2-BrNQ) and 2-BrNQ on silver nanoparticles. Surface-Enhanced Raman Scattering (SERS) spectra of 2-BrNQ adsorbed on silver nanoparticles were investigated. The CO, CH in-plane bending and CBr stretching modes were enhanced in SERS spectrum with respect to normal Raman spectrum. The spectral analysis reveals that the 2-BrNQ adsorbed 'stand-on' orientation on the silver surface. Density Functional Theory (DFT) calculations are also performed to study the vibrational features of 2-BrNQ molecule and 2-BrNQ molecule on silver surface.
Topics: Adsorption; Metal Nanoparticles; Models, Molecular; Naphthoquinones; Powder Diffraction; Quantum Theory; Silver; Spectrum Analysis, Raman; Surface Properties; X-Ray Diffraction
PubMed: 25481490
DOI: 10.1016/j.saa.2014.11.009