scholarly journals Recrystallization and Production of Spherical Submicron Particles of Sulfasalazine Using a Supercritical Antisolvent Process

Crystals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 295
Author(s):  
Wei-Yi Wu ◽  
Chie-Shaan Su
Keyword(s):  
Solid State ◽  
Solution Concentration ◽  
Crystal Form ◽  
Lower Solution ◽  
Nozzle Diameter ◽  
Submicron Particles ◽  
Spherical Particles ◽  
Crystal Habit ◽  
Operating Pressure ◽  
Supercritical Antisolvent

In this study, the recrystallization and production of spherical submicron particles of sulfasalazine, an active pharmaceutical ingredient (API), were performed using the supercritical antisolvent (SAS) process, a nonconventional crystallization technique. Sulfasalazine was dissolved in tetrahydrofuran (THF), and supercritical carbon dioxide (CO2) served as the antisolvent. The effects of operating parameters on the SAS process, including the operating pressure, solution concentration, solution flowrate, CO2 flowrate, and spraying nozzle diameter, at two operating temperatures were examined. The solid-state characteristics of sulfasalazine before and after the SAS process, including particle size, crystal habit, and crystal form, were analyzed using a scanning electron microscope (SEM), powder X-ray diffractometer (PXRD), and differential scanning calorimeter (DSC). A higher operating temperature, intermediate operating pressure, higher CO2 flowrate, and lower solution flowrate are recommended to obtain spherical particles of sulfasalazine. The effects of the solution concentration and spraying nozzle diameter on the SAS process were negligible. Under optimal conditions, spherical sulfasalazine crystals with a mean size of 0.91 μm were generated, and this study demonstrated the feasibility for tuning the solid-state characteristics of API through the SAS process.

scholarly journals Preparation of Cefquinome Nanoparticles by Using the Supercritical Antisolvent Process

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Xiao Kefeng ◽  
Wang Weiqiang ◽  
Hu Dedong ◽  
Hao Zhihui ◽  
Qu Yanpeng ◽  
...  
Keyword(s):  
Particle Size ◽  
Univariate Analysis ◽  
Average Diameter ◽  
Solution Concentration ◽  
Flow Speed ◽  
Operating Pressure ◽  
Individual Factor ◽  
Solution Flow ◽  
Supercritical Antisolvent ◽  
Orthogonal Experiments

The supercritical antisolvent process was used successfully to prepare nanoparticles of cefquinome. These particles were observed by scanning electron microscope (SEM) and their average diameter was measured by laser particle size analyzer. In the experiments, dimethyl sulfoxide (DMSO) was selected as solvent to dissolve cefquinome sulfate. It was confirmed by orthogonal experiments that the concentration of solution was the primary factor in this process followed by feeding speed of solution, precipitation pressure, and precipitation temperature. Moreover, the optimal conditions of preparing nanoparticles of cefquinome by supercritical antisolvent process were that solution concentration was 100 mg/mL, solution flow speed was 1.5 mL/min, operating pressure was 13 Mpa, and operating temperature was 33°C. Confirmatory experiment was conducted under this condition. It was found that the appearance of particles was flakes and the average diameter of particles was 0.71 microns. Finally, influence law of individual factor on particle size was investigated by univariate analysis.

scholarly journals Applications of Supercritical Anti-Solvent Process in Preparation of Solid Multicomponent Systems

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 475
Author(s):  
Guijin Liu ◽  
Junjian Li ◽  
Shiming Deng
Keyword(s):  
Solid State ◽  
Solid Dispersions ◽  
Crystal Form ◽  
Great Promise ◽  
Computational Techniques ◽  
Large Contribution ◽  
Continuous Manufacturing ◽  
Multicomponent Systems ◽  
On Line ◽  
Underlying Mechanisms

Solid multicomponent systems (SMS) are gaining an increasingly important role in the pharmaceutical industry, to improve the physicochemical properties of active pharmaceutical ingredients (APIs). In recent years, various processes have been employed for SMS manufacturing. Control of the particle solid-state properties, such as size, morphology, and crystal form is required to optimize the SMS formulation. By utilizing the unique and tunable properties of supercritical fluids, supercritical anti-solvent (SAS) process holds great promise for the manipulation of the solid-state properties of APIs. The SAS techniques have been developed from batch to continuous mode. Their applications in SMS preparation are summarized in this review. Many pharmaceutical co-crystals and solid dispersions have been successfully produced via the SAS process, where the solid-state properties of APIs can be well designed by controlling the operating parameters. The underlying mechanisms on the manipulation of solid-state properties are discussed, with the help of on-line monitoring and computational techniques. With continuous researching, SAS process will give a large contribution to the scalable and continuous manufacturing of desired SMS in the near future.

scholarly journals Synthesis of Silica Particles Using Ultrasonic Spray Pyrolysis Method

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 463
Author(s):  
Srecko Stopic ◽  
Felix Wenz ◽  
Tatjana-Volkov Husovic ◽  
Bernd Friedrich
Keyword(s):  
Spray Pyrolysis ◽  
Sol Gel ◽  
Ultrasonic Spray Pyrolysis ◽  
Silica Particles ◽  
Cement Industry ◽  
Submicron Particles ◽  
Spherical Particles ◽  
Spray Pyrolysis Method ◽  
X Ray ◽  
Ultrasonic Spray

Silica has sparked strong interest in hydrometallurgy, catalysis, the cement industry, and paper coating. The synthesis of silica particles was performed at 900 °C using the ultrasonic spray pyrolysis (USP) method. Ideally, spherical particles are obtained in one horizontal reactor from an aerosol. The controlled synthesis of submicron particles of silica was reached by changing the concentration of precursor solution. The experimentally obtained particles were compared with theoretically calculated values of silica particles. The characterization was performed using a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). X-ray diffraction, frequently abbreviated as XRD, was used to analyze the structure of obtained materials. The obtained silica by ultrasonic spray pyrolysis had an amorphous structure. In comparison to other methods such as sol–gel, acidic treatment, thermal decomposition, stirred bead milling, and high-pressure carbonation, the advantage of the ultrasonic spray method for preparation of nanosized silica controlled morphology is the simplicity of setting up individual process segments and changing their configuration, one-step continuous synthesis, and the possibility of synthesizing nanoparticles from various precursors.

scholarly journals Cefquinome Controlled Size Submicron Particles Precipitation by SEDS Process Using Annular Gap Nozzle

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Kefeng Xiao ◽  
Weiqiang Wang ◽  
Dedong Hu ◽  
Yanpeng Qu ◽  
Zhihui Hao ◽  
...  
Keyword(s):  
Particle Size ◽  
Xrd Analysis ◽  
Solution Concentration ◽  
Operating Conditions ◽  
Submicron Particles ◽  
Optimal Operating ◽  
Surface Appearance ◽  
Precipitation Temperature ◽  
Annular Gap ◽  
Feeding Speed

An annular gap nozzle was applied in solution enhanced dispersion by supercritical fluids (SEDS) process to prepare cefquinome controlled size submicron particles so as to enhance their efficacy. Analysis results of orthogonal experiments indicated that the concentration of solution was the primary factor to affect particle sizes in SEDS process, and feeding speed of solution, precipitation pressure, and precipitation temperature ranked second to fourth. Meanwhile, the optimal operating conditions were that solution concentration was 100 mg/mL, feeding speed was 9 mL/min, precipitation pressure was 10 MPa, and precipitation temperature was 316 K. The confirmatory experiment showed that D50 of processed cefquinome particles in optimal operating conditions was 0.73 μm. Moreover, univariate effect analysis showed that the cefquinome particle size increased with the increase of concentration of the solution or precipitation pressure but decreased with the increase of solution feeding speed. When precipitation temperature increased, the cefquinome particle size showed highest point. Moreover, characterization of processed cefquinome particles was analyzed by SEM, FT-IR, and XRD. Analysis results indicated that the surface appearance of processed cefquinome particles was flakes. The chemical structure of processed cefquinome particles was not changed, and the crystallinity of processed cefquinome particles was a little lower than that of raw cefquinome particles.

On the interaction of azithromycin monohydrate with metallic containers

2006 ◽  
Vol 39 (6) ◽  
pp. 826-830 ◽  
Author(s):  
J. Montejo-Bernardo ◽  
S. García-Granda ◽  
M. Bayod-Jasanada ◽  
I. Llorente ◽  
L. Llavona
Keyword(s):  
Crystal Form ◽  
Crystal Habit ◽  
Metallic Surfaces ◽  
Crystal Face ◽  
Great Propensity ◽  
Erythromycin A ◽  
Semisynthetic Derivative

The monohydrate form of azithromycin (an antibiotic semisynthetic derivative of erythromycin A) is difficult to manipulate due to its great propensity to stick to metallic surfaces (during crystallization, drying, grinding,etc.). In this paper, this behaviour is explained on the basis of the conformation and packing of the azithromycin molecules in this crystal form. In particular, the crystal habit favours interaction between the N and O atoms with the metal through one particular crystal face.

Electron Microscopy Study of Submicron Size Antiferromagnetic KMnF3 Nanoparticles and Their Self-assembly

2003 ◽  
Vol 775 ◽  
Author(s):  
Jeffrey Anderson ◽  
Rubi Garcia ◽  
Weilie L. Zhou
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Room Temperature ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Submicron Particles ◽  
Spherical Particles ◽  
Large Area ◽  
Homogeneous Crystal ◽  
Field Emission Electron Microscopy

AbstractSubmicron KMnF3 cubic and spherical nanoparticles were synthesized using the reverse micelle method. The nanostructures of the nanocrystals were studied by field emission electron microscopy and transmission electron microscopy. KMnF3 nanocrystals synthesized at room temperature started with cubic submicron particles (∼100 nm) and consisted of KMnF3 nanocrystallites (10-15 nm). As the reaction continued, the nanocrystals fused together and transformed into perfect cubic nanocrystals. Spherical beads composed of KMnF3 nanocrystallites were observed at low temperature synthesis. As the reaction continued, the spherical particles grew larger, however, no characteristic cubic shape of KMnF3 nanoparticles were observed. Even as they grew larger, there was no evidence of homogeneous crystal morphology as seen in the room temperature samples. Cubic shape KMnF3 nanocrystals were self-assembled into large area self-assembling patterns.

Fundamentals

2020 ◽  
pp. 41-77
Author(s):  
Joel Bernstein
Keyword(s):  
Fusion Rule ◽  
Crystal Form ◽  
Crystal Habit ◽  
Heat Of Fusion ◽  
Transition Rule ◽  
Phase Rule ◽  
Entropy Of Fusion ◽  
Thermodynamic Relationships ◽  
Heat Of Transition ◽  
Definition Of

The physical and structural fundamentals of polymorphism are introduced, including a review of the phase rule and the thermodynamic relations in polymorphs. The latter are used to introduce energy–temperature diagrams, leading to the definition of the concepts enantiotropism and monotropism describing the thermodynamic relationships between and among polymorphs with appropriate examples. The alternate representation of phase diagram in terms of pressure and temperature is also presented. These lead to a number of rules regarding the relationships between polymorphs and ways to understand and predict some important physical properties: the heat-of-transition rule, the heat-of-fusion rule, the entropy-of-fusion rule, the heat-capacity rule, the density rule, and the infrared rule. Structural aspects include the distinction between crystal form and crystal habit and methods for characterizing and comparing structures in polymorphic systems. Current developments are discussed that deal with the ramifications of nanoscale situations on structural concepts and thermodynamic relationships.

Surface Morphology Studies on Laser Irradiated Target and Bi(Pb)SrCaCuO Thin Films

2020 ◽  
Vol 995 ◽  
pp. 89-93
Author(s):  
A.N. Jannah ◽  
S.A. Halim ◽  
H. Abdullah
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Surface Morphology ◽  
Single Crystal ◽  
Second Harmonic ◽  
Pulsed Laser ◽  
Bulk Sample ◽  
Spherical Particles ◽  
Variable Pressure ◽  
Scanning Electron

In this study, pulsed laser deposition technique was used to deposit bismuth plumbum strontium calcium copper oxide {Bi (Pb)SrCaCu0} thin films on MgO single crystal substrate. Solid state procedure which is inexpensive technique used in the production process of the Bi (Pb)SrCaCu0 superconductor bulk sample. In this work, Handy YAG Lasers (model: HYL 101 E) has been used. It is a high power class 4 solid state (ND: YAG) Q-switched pulsed laser and 532 nm (visible green: second harmonic) has been used to ablate the films. The substrate used in this work was single crystal MgO with the (100) orientation. Scanning Electron Microscopy (SEM) was used to observe the microstructure of fracture surface and cross section of thin film materials. Variable Pressure Scanning Electron Microscope (LEO-VPSEM) was used to study the correlation between the microstructure features. SEM studies have shown that the surface morphology of the bulk sample comprises platelets of average size ≈10μm with uniform and homogenous microstructure. The typical morphology of the as deposited films showed a continuous phase, granular structure, which spherical particles up to 5μm in diameter. The most prominent types of particulates BPSCCO films on MgO substrate are droplets with smooth surface, bigger droplets with granular surface, spherically-shaped features confined by randomly oriented facets, submicron rod-like features, Cu-enriched needles, platelets, irregularly-shaped Cu-rich outgrowths, strongly Cu-enriched tabular outgrowths, big target fragments, island growth structure, cubic and rectangular cubic structures. SEM analysis also showed that the deposition time have a pronounced influence on the particle size. The target morphology, which develops under laser-irradiation, depends on the laser fluence and the technique, by which the laser beam is moved relatively to the target during ablation. Laser-irradiated surfaces normally become altered both physically and chemically and morphological changes take the form of periodic structures such as ripples and ridges.

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