scholarly journals Improving Relative Bioavailability of Oral Imidazolidinedione by Reducing Particle Size Using Homogenization and Ultra-Sonication

2019 ◽  
Vol 184 (Supplement_1) ◽  
pp. 106-113
Author(s):  
Qiang Zeng ◽  
Lisa Xie ◽  
Jing Zhang ◽  
Chau Vuong ◽  
Brittney Potter ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Diameter ◽  
Relative Bioavailability ◽  
Homogenization Method ◽  
Radical Cure ◽  
Significant Difference ◽  
Sonic Energy ◽  
Probe Sonication ◽  
Relapsing Malaria ◽  
Mean Particle Diameter

Abstract Particle size is an important determinant of gastrointestinal absorption of compounds administrated orally. The present study evaluates the effect of a reduction in particle size assessed by homogenization, sonication, and homogenization plus sonication on the bioavailability of imidazolidinedione (IZ), an antimalarial compound with known causal prophylactic activity and radical cure of relapsing malaria. Formulations were administrated intragastrically to mice, and blood samples were collected for LC-MS/MS analysis. The homogenization method manually decreased particle size with minimal variance, resulting in a mean particle diameter of 42.22 μm, whereas the probe sonication method evenly distributed pulses of sound to break apart particles, resulting in a mean diameter of 1.50 μm. Homogenization plus sonication resulted in a mean particle diameter of 1.44 μm, which was similar to that of the sonication method alone. The compound suspensions did not show a significant difference in mean particle size between the different vehicles. The sonically engineered microparticle delivers high sonic energy to the suspension leads to faster breakdown and stabilizing of the micronized particles when compared with homogenizer. The bioavailability of the small particle IZ formulation was 100%, compared to the 55.79% relative bioavailability of IZ with larger particle size. These initial data clearly show that a reduction in particle size of orally administered IZ with probe sonication could significantly increase bioavailability in rodent animals that is affected by a high first-pass effect.

Effect of Ion Exchange Resin Particle Size on X-Ray Fluorescent Analysis

1971 ◽  
Vol 15 ◽  
pp. 534-538
Author(s):  
A. L. Allen ◽  
V. C. Rose
Keyword(s):  
Particle Size ◽  
Copper Concentration ◽  
Exchange Resin ◽  
Particle Diameter ◽  
Ion Exchange Resin ◽  
General Shape ◽  
X Ray ◽  
A Minor ◽  
The Relationship ◽  
Mean Particle Diameter

The effect of resin particles on copper x-ray fluorescence was studied. For any given resin size the relationship between copper concentration and x-ray intensity was linear. As the particle size decreased, the x-ray intensity increased for any given copper concentration. The general shape of the curves are similar to the ones predicted by Bernstein for a minor constituent in a power sample. This study indicates that the variation in intensity with particle size can be eliminated by using resins with a mean particle diameter of 56 microns or less.

Influence of Fluidization Velocity on Bed Defluidization in Fluidized Bed Combustors

2005 ◽  
Author(s):  
Mohammad R. Golriz ◽  
Morgan Eriksson ◽  
Marcus O¨hman ◽  
Anders Nordin ◽  
Rainer Backman
Keyword(s):  
Particle Size ◽  
Fluidized Bed ◽  
Large Scale ◽  
Particle Diameter ◽  
Operating Conditions ◽  
Biomass Combustion ◽  
Gas Velocity ◽  
Fluidization Velocity ◽  
Significant Difference ◽  
Superficial Gas Velocity

Effects of superficial gas velocity and bed particle size on bed defluidization during biomass combustion were investigated. Sampled bed particles from four different large-scale circulating- and bubbling fluidized bed combustors, using biomass as fuel, were collected and analyzed. The bed particles from each fluidized bed unit were divided into small and large particle size fractions. The results indicate no significant difference in elemental compositions between small and large coated bed particles but the ratio of coating thickness to the mean particle diameter was higher for the small particles compared to the large ones. Controlled fluidized bed agglomeration tests revealed strong influence from fluidization velocity on initial defluidization temperatures at lower velocities, but little effect at higher velocities. Influence of bed particle size on initial defluidization temperature varied depending on operating conditions. Finally, a model based on viscous flow sintering is proposed for the relation between agglomeration temperature and superficial gas velocity. The model predictions are in good agreement with experimental data.

PARTICLE SIZE OF DDT WETTABLE POWDERS IN RELATION TO TOXICITY

1947 ◽  
Vol 79 (11-12) ◽  
pp. 216-221
Author(s):  
G. G. Dustan ◽  
W. L. Putman
Keyword(s):  
Particle Size ◽  
Field Test ◽  
Particle Diameter ◽  
Codling Moth ◽  
Potato Leafhopper ◽  
Review Of The Literature ◽  
House Flies ◽  
Mean Particle Diameter

It is generally considered that the smaller the particle size of insecticides applied as solids, the greater is their effectiveness. Smith and Goodhue (1) arrived at his conclusion after a review of the literature. Woodruff and Turner (4) showed that decrease in particle size of DDT wettable powders increased the toxicity of the residues against house flies, and that correspondingly better results were obtained from the residues of smallest particle size in a field test against potato leafhopper and fleabeetles. Steiner et al. (2), who have done much work on the effect of DDT particle size on codling moth control, stated that for this purpose the optimum surface mean particle diameter for DDT lies between 2.5 and 5 microns.

CFD Simulation of Spouted Bed Working with a Size Distribution of Sand Particles: Segregation Aspects

2017 ◽  
Vol 899 ◽  
pp. 95-100
Author(s):  
Kássia Graciele dos Santos ◽  
L.V. Ferreira ◽  
Ricardo Correa Santana ◽  
Marcos Antonio de Souza Barrozo
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Cfd Simulation ◽  
Computational Simulation ◽  
Particle Diameter ◽  
Spouted Bed ◽  
Particle Segregation ◽  
Cfd Method ◽  
Mean Particle Diameter

Spouted bed simulations are usually performed using only one granular phase with a mean particle diameter representing the entire particle mixture, instead of a particle size distribution. In this study, the effect of the particle size distribution is accounted through the simulation of a mixture with five granular phases. The results showed that the particle segregation occurs. Larger particles are more concentrated in the upper region, while the smaller particles are preferably positioned in the lower region of the bed. Computational simulation using CFD method reproduced well the segregation experiments with different participle sizes of sand.

scholarly journals Influence of combined hydrolyzed collagen and maltodextrin as carrier agents in spray drying of cocona pulp

2020 ◽  
Vol 23 ◽  
Author(s):  
Diana Patricia Vargas-Muñoz ◽  
Louise Emy Kurozawa
Keyword(s):  
Particle Size ◽  
Spray Drying ◽  
Chemical Structure ◽  
Particle Diameter ◽  
Spray Dryer ◽  
Drying Process ◽  
Hydrolyzed Collagen ◽  
Bioactive Properties ◽  
Encapsulation Process ◽  
Mean Particle Diameter

Abstract This work aimed to evaluate the effect of carrier agents containing maltodextrin and protein, represented by hydrolyzed collagen on the spray drying process of cocona (Solanum sessiliflorum Dunal), and on the properties of the resulting powders. We used pre-established proportions between the solids of cocona pulp and the carrier agents (P:CA), and among carrier agents themselves, maltodextrin and hydrolyzed collagen, (MD:HC). The process was carried out in a spray dryer at an inlet air temperature of 120 ºC. We prepared twelve feed solutions containing 20% of total solids, with P:CA ratios of 1:3, 1:4, 1:5 and 1:6, and MD:HC ratios of 0:100, 50:50, and 100:0. Solids recovery was obtained for the evaluation of the spray drying process. The cocona pulp powders were analyzed for moisture content, water activity, particle size distribution, mean particle diameter, chemical structure (FTIR) and color. For a P:CA of 1:6, for the sample formulated with hydrolyzed collagen only, solids recovery (96.2%) was much higher than that of the sample with maltodextrin only (39.2%). The chemical structure of cocona powders can be considered a sign of a good encapsulation process. The color of the cocona pulp powder was similar to that of the carrier agents. The formulation with highest content of hydrolyzed collagen improved the recovery of solids, guaranteed the cocona pulp encapsulation, and obtained fruit powders with bioactive properties.

Carbon Black Particle Size

1953 ◽  
Vol 26 (4) ◽  
pp. 912-918
Author(s):  
C. H. Leigh-Dugmore
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Carbon Black ◽  
Specific Surface ◽  
Particle Diameter ◽  
Nitrogen Adsorption ◽  
Carbon Black Particle ◽  
Mean Diameter ◽  
Black Particle ◽  
Mean Particle Diameter

Abstract Carbon black particle diameters tend to be distributed log-normally. This discovery has led, first, to simplified methods for the calculation of mean diameter and specific surface from electron microscope measurements; second, to a demonstration that the observed differences between estimates of surface area from electron-microscope measurements and from low-temperature nitrogen adsorption measurements cannot be entirely explained by supposing the finest particles not to be resolved by the electron microscope, thus adding further support to the porosity explanation; and third, to the argument that any two size characteristics, such as mean particle diameter and specific surface, are entirely sufficient to describe particle size and its distribution and, consequently, their influence on vulcanizate properties.

Aerosol Synthesis of Aluminum Nitride Powders

1991 ◽  
Vol 249 ◽  
Author(s):  
Albert A. Adjaottor ◽  
Gregory L. Griffin
Keyword(s):  
Particle Size ◽  
Residence Time ◽  
Particle Diameter ◽  
Aerosol Formation ◽  
Yield Efficiency ◽  
Operating Variables ◽  
Aerosol Process ◽  
The Mean ◽  
Diffusive Mixing ◽  
Mean Particle Diameter

ABSTRACTWe describe a new laboratory-scale aerosol process for producing AIN powder. A two-stage reactor design is used. In the first stage, triethyl aluminum (TEA = AI(CC2H5 )3) and NH3 react to form an aerosol adduct in a laminar flow diffusive mixing zone. The aerosol then enters the furnace stage, where it is converted to AIN. We have examined the influence of the major operating variables (e.g., inlet TEA concentration, reactor residence time, and furnace temperature) on the particle size and distribution, yield, and efficiency. For example, increasing the TEA concentration from 0.12 to 1.30 µmol/cm3 causes an increase in the mean particle diameter (from 0.07 to 0.13 Pim), a slight increase in polydispersity (from 0.31 to 0.43), and a decrease in yield efficiency (from 90% to 73%). In contrast, decreasing the reactor residence time (by increasing the flow rate) has little effect on mean particle diameter, but causes a significant increase in yield efficiency (approaching 100%). The overall behavior of the reactor suggests a model in which the particle size distribution of the final product is determined primarily by the aerosol formation steps in the mixing stage (i.e., nucleation, growth, and coalescence), while the composition and crystallinity of the product are determined by furnace conditions.

Optical Measurement of Gas Turbine Engine Soot Particle Effluents

1998 ◽  
Vol 120 (1) ◽  
pp. 69-76 ◽  
Author(s):  
R. J. Litchford ◽  
F. Sun ◽  
J. D. Few ◽  
J. W. L. Lewis
Keyword(s):  
Particle Size ◽  
Distribution Function ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Gas Turbine ◽  
Soot Particle ◽  
Particle Diameter ◽  
Noise Component ◽  
Multi Wavelength ◽  
Mean Particle Diameter

This paper addresses optical-based techniques for measuring soot particulate loading in the exhaust stream of gas turbine engines. The multi-angle scattering and multi-wavelength extinction of light beams by ensembles of submicrometer soot particles was investigated as a diagnostic means of inferring particle field characteristics. This is, the particle size distribution function and particle number density were deduced using an innovative downhill simplex inversion algorithm for fitting the deconvolved Mie-based scattering/extinction integral to the measured scattering/extinction signals. In this work, the particle size distribution was characterized by the widely accepted two-parameter log-normal distribution function, which is fully defined with the specification of the mean particle diameter and the standard deviation of the distribution. The accuracy and precision of the algorithm were evaluated for soot particle applications by applying the technique to noise-perturbed synthetic data in which the signal noise component is obtained by Monte Carlo sampling of Gaussian distributed experimental errors of 4, 6, and 10 percent. The algorithm was shown to yield results having an inaccuracy of less than 10 percent for the highest noise levels and an imprecision equal to or less than the experimental error. Multi-wavelength extinction experiments with a laboratory bench-top burner yielded a mean particle diameter of 0.039 μm and indicated that molecular absorption by organic vapor-phase molecules in the ultraviolet region should not significantly influence the measurements. A field demonstration test was conducted on one of the JT-12D engines of a Sabre Liner jet aircraft. This experiment yielded mean diameters of 0.040 μm and 0.036 μm and standard deviations of 0.032 μm and 0.001 μm for scattering and extinction methods, respectively. The total particulate mass flow rate at idle was estimated to be 0.54 kg/h.

scholarly journals Preparation of Lipid Nanoemulsions Incorporating Curcumin for Cancer Therapy

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Songyot Anuchapreeda ◽  
Yoshinobu Fukumori ◽  
Siriporn Okonogi ◽  
Hideki Ichikawa
Keyword(s):  
Particle Size ◽  
Physical Stability ◽  
Particle Diameter ◽  
Leukemic Cell ◽  
Egg Yolk ◽  
Leukemic Cell Lines ◽  
Cytotoxicity Studies ◽  
Lipid Nanoemulsion ◽  
New Formulation ◽  
Mean Particle Diameter

The aim of this study was to develop a new formulation of a curcumin lipid nanoemulsion having the smallest particle size, the highest loading, and a good physical stability for cancer chemotherapy. Curcumin lipid nanoemulsions were prepared by a modified thin-film hydration method followed by sonication. Soybean oil, hydrogenatedL-α-phosphatidylcholine from egg yolk, and cosurfactants were used to formulate the emulsions. The resultant nanoemulsions showed mean particle diameter of 47–55 nm, could incorporate 23–28 mg curcumin per 30 mL, and were stable in particle size for 60 days at 4°C. The cytotoxicity studies of curucumin solution and curcumin-loaded nanoemulsion using B16F10 and leukemic cell lines showed IC50values ranging from 3.5 to 30.1 and 22.2 to 53.7 μM, respectively. These results demonstrated the successful incorporation of curcumin into lipid nanoemulsion particles with small particle size, high loading capacity, good physical stability, and preserved cytotoxicity.

Solubility and Micronization of Ganciclovir

2011 ◽  
Vol 393-395 ◽  
pp. 1421-1426
Author(s):  
Feng Xiang Tang ◽  
Yun Zhang ◽  
Su Na Lin ◽  
Zhong Li Guo
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Particle Diameter ◽  
Absolute Bioavailability ◽  
Stabilizing Agents ◽  
Ph Values ◽  
Solubility Behavior ◽  
The Mean ◽  
Liquid Precipitation ◽  
Mean Particle Diameter

Ganciclovir (GCV) is only slightly soluble in water and hence oral GCV gives low absolute bioavailability. Liquid precipitation is an effective way to prepare micro-sized drug particles. The solubility of GCV in several solvents or in aqueous solution at different pH values was determined. According to its solubility behavior, reactive precipitation was suggested as the micronization method of GCV. The mean particle diameter of micronized GCV powder was around 15~20 μm, smaller than that of raw GCV powder, and the size distribution of micronized GCV was narrower than that of raw GCV. The stirring rate, the type and addition of stabilizing agents seemed to have no significant effect on the particle size of micronized GCV. Micronized GCV showed much faster dissolution rate than raw GCV.

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