scholarly journals Microflow Nanoprecipitation of Positively Charged Gastroresistant Polymer Nanoparticles of Eudragit® RS100: A Study of Fluid Dynamics and Chemical Parameters

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2925 ◽  
Author(s):  
Cristina Yus ◽  
Manuel Arruebo ◽  
Silvia Irusta ◽  
Victor Sebastián
Keyword(s):  
Fluid Dynamics ◽  
Particle Size ◽  
Flow Rate ◽  
Physicochemical Parameters ◽  
Polymer Concentration ◽  
Critical Parameters ◽  
Synthesis Process ◽  
Size Analysis ◽  
Solvent Ratio ◽  
Microscopy Imaging

The objective of the present work was to produce gastroresistant Eudragit® RS100 nanoparticles by a reproducible synthesis approach that ensured mono-disperse nanoparticles under the size of 100 nm. Batch and micromixing nanoprecipitation approaches were selected to produce the demanded nanoparticles, identifying the critical parameters affecting the synthesis process. To shed some light on the formulation of the targeted nanoparticles, the effects of particle size and homogeneity of fluid dynamics, and physicochemical parameters such as polymer concentration, type of solvent, ratio of solvent to antisolvent, and total flow rate were studied. The physicochemical characteristics of resulting nanoparticles were studied applying dynamic light scattering (DLS) particle size analysis and electron microscopy imaging. Nanoparticles produced using a micromixer demonstrated a narrower and more homogenous distribution than the ones obtained under similar conditions in conventional batch reactors. Besides, fluid dynamics ensured that the best mixing conditions were achieved at the highest flow rate. It was concluded that nucleation and growth events must also be considered to avoid uncontrolled nanoparticle growth and evolution at the collection vial. Further, rifampicin-encapsulated nanoparticles were prepared using both approaches, demonstrating that the micromixing-assisted approach provided an excellent control of the particle size and polydispersity index. Not only the micromixing-assisted nanoprecipitation promoted a remarkable control in the nanoparticle formulation, but also it enhanced drug encapsulation efficiency and loading, as well as productivity. To the best of our knowledge, this was the very first time that drug-loaded Eudragit® RS100 nanoparticles (NPs) were produced in a continuous fashion under 100 nm (16.5 ± 4.3 nm) using microreactor technology. Furthermore, we performed a detailed analysis of the influence of various fluid dynamics and physicochemical parameters on the size and uniformity of the resulting nanoparticles. According to these findings, the proposed methodology can be a useful approach to synthesize a myriad of nanoparticles of alternative polymers.

Study on the Reaction Process of Ploy-High-Ferric-Silicic Coagulant

2010 ◽  
Vol 156-157 ◽  
pp. 1074-1077
Author(s):  
Yan Zhen Yu ◽  
Juan Tan ◽  
Yong Sun
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Theoretical Basis ◽  
Raw Materials ◽  
Particle Size Analysis ◽  
Synthesis Process ◽  
Size Analysis ◽  
Potassium Ferrate ◽  
Transmission Electron ◽  
Complexation Process

A new inorganic polymer coagulant，ploy-high-ferric-silicic coagulant with various Si/FeO42- ratios and salt-basicity, was prepared using the fly ash extract and potassium ferrate. The influence of both Si/FeO42- ratios and salt-basicity on the complexation process was explored with many analytical methods, such as transmission electron microscope (TEM), lased particle size analysis (LPSA) and infrared spectrum (IR). The results show that the ploy-high-ferric-silicic is a complexation compound, instead of a simple mixture of raw materials. The complexation process between Si and Fe may be different from various Si/FeO42- ratios and salt-basicity. The bonding can help revealing the high-ferric groups function in synthesis process. From analyzing the different ferrosilicon bonding modes, it can provide some theoretical basis to compound high-ferric coagulant.

scholarly journals Preparation of Associative Polyurethane Thickener and Its Thickening Mechanism Research

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Gao Nan ◽  
Zhang Zhuo ◽  
Dong Qingzhi
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Soft Segment ◽  
Synthesis Process ◽  
Segment Length ◽  
Solvent Ratio ◽  
Aqueous Dispersions ◽  
Before And After ◽  
Size And Morphology ◽  
End Capping

Associative polyurethane (PU) thickener has been synthesized by preparing the prepolymer with the reaction of polyethylene glycol (PEG) and isophorone diisocyanate (IPDI), which then end-capping with long-chain alkanol. The synthesis process, as well as hydrophilic chain length, theoretical molecular weight, solvent ratio, and thickener percentages, has been researched. The results shows that it reaches the upmost thickening effect when the theoretical molecular weight is under 20000, soft-segment length is under 4000, solvent ratio is 1 : 1, and thickener percentages are controlled at 10%. Furthermore, thickening mechanism of PU thickener has been analyzed detailedly through the measurement of the critical micelle concentration (CMC) of PU thickener and analysis of the influence of PU thickener on the particle size and morphology of PU dispersions. It has been observed from the scanning electron microscopy (SEM) that the PU aqueous dispersions produce a certain degree of flocculation when the PU thickener was added, and this flocculation structure has been proved to be a thixotropic structure through the characterization of the change of particle size before and after the thickener is introduced into the PU aqueous dispersions. The CMC measurement results present that the thickening effect will be apparent when the concentration is controlled in a low range.

scholarly journals Synthesis of ZnO-CdO Nanocomposites

2013 ◽  
Vol 1 (1) ◽  
pp. 11-14
Author(s):  
N. Sahu ◽  
◽  
R. K. Duchaniya ◽  
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Low Cost ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Synthesis Process ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The ZnO-CdO nanocomposite was prepared by sol-gel method by using their respective nitrates. It is a simple and low cost method to prepare nanocomposites. The drying temperature and drying period of prepared gel was varied during the synthesis process. The prepared samples were characterized by using scanning electron microscope (SEM), particle size analysis (PSA), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL) to get surface morphology, idea of getting particle of nanosized range so that further characterizations can be done, to study the optical property of synthesized nanocomposite and measure the band gap . The grain size determined by Scherrer’s formula was found to be between 30-50 nm.

Influence of Albumin in the Microfluidic Synthesis of PEG-PLGA Nanoparticles

2019 ◽  
Vol 7 (6) ◽  
pp. 460-468 ◽  
Author(s):  
Bettina Poller ◽  
Gavin F. Painter ◽  
Greg F. Walker
Keyword(s):  
Particle Size ◽  
Aqueous Phase ◽  
Flow Rate ◽  
Coefficient Of Variation ◽  
Polymer Concentration ◽  
Plga Nanoparticles ◽  
Organic Polymer ◽  
Flow Rate Ratio ◽  
Aqueous Solvent ◽  
Average Size

Background: A key challenge in the manufacturing of polymeric colloids is producing nanoparticles with good batch-to-batch consistency. Objective: Develop a robust microfluidics method for the preparation of PEG-PLGA nanoparticles using dimethyl sulfoxide (DMSO) as the organic phase solvent for the encapsulation of DMSO soluble agents. Method: Microfluidic process parameters, total flow rate (10 mL/min), flow rate ratio (1:1) of the aqueous phase and the organic polymer solution, and polymer concentration (5 mg/ml). Polyvinyl alcohol (PVA) or human serum albumin (HSA) was included in the aqueous phase. Dynamic light scattering and transmission electron microscopy were used to investigate the size and morphology of particles. Results: PLGA nanoparticles made using DMSO with the aqueous solvent containing PVA (2%) had an average size of 60 nm while PLGA-PEG nanoparticles made with and without PVA (2%) had an average size of 70 and 100 nm, respectively. PLGA-PEG nanoparticles generated with or without PVA had a high batch-to-batch coefficient of variation for the particle size of 20% while for PLGA nanoparticles with PVA it was 4%. HSA added to the aqueous phase reduced the size and the zeta potential of PEG-PLGA nanoparticles as well the batch-to-batch coefficient of variation for particle size to < 5%. Nanoparticles were stable in solution and after lyophilized in the presence of sucrose. Conclusion: Albumin was involved in the self-assembly of PEG-PLGA nanoparticles altering the physicochemical properties of nanoparticles. Adding protein to the aqueous phase in the microfluidic fabrication process may be a valuable tool for tuning the properties of nanoparticles and improving batch-to-batch consistency.

scholarly journals Size mapping of electric field-assisted production of polycaprolactone particles

2010 ◽  
Vol 7 (suppl_4) ◽  
Author(s):  
M. Enayati ◽  
Z. Ahmad ◽  
E. Stride ◽  
M. Edirisinghe
Keyword(s):  
Particle Size ◽  
Electric Field ◽  
Size Distribution ◽  
Flow Rate ◽  
Applied Voltage ◽  
Polymer Concentration ◽  
Extensive Study ◽  
Uv Spectrophotometry ◽  
Polymeric Particles ◽  
Stable Cone

In this investigation, biodegradable polycaprolactone polymeric particles (300–4500 nm in diameter) were prepared by jetting a solution in an electric field. An extensive study has been carried out to determine how the size and size distribution of the particles generated can be controlled by systematically varying the polymer concentration in solution (and thereby its viscosity and electrical conductivity), and also the selected flow rate (2–50 µl min −1 ) and applied voltage (0–15 kV) during particle generation. Change in these parameters affects the mode of jetting, and within the stable cone-jet mode window, an increase in the applied voltage (approx. 15 kV) resulted in a reduction in particle size and this was more pronounced at high flow rates (such as; 30, 40 and 50 µl min −1 ) in the same region. The carrier particles were more polydisperse at the peripheral regions of the stable cone-jet mode, as defined in the applied voltage-flow rate parametric map. The effect of loading a drug on the particle size, size distribution and encapsulation efficiency was also studied. Release from drug-loaded particles was investigated using UV spectrophotometry over 45 days. This work demonstrates a powerful method of generating drug-loaded polymeric particles, with the ability to control size and polydispersivity, which has great potential in several categories of biotechnology requiring carrier particles, such as drug delivery and gene therapy.

scholarly journals Studies on the Preparation of Nanoparticles from Betulin-Based Polyanhydrides

2021 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Daria Niewolik ◽  
Grzegorz Dzido ◽  
Katarzyna Jaszcz
Keyword(s):  
Particle Size ◽  
Organic Phase ◽  
Significant Influence ◽  
Methylene Chloride ◽  
Polymer Concentration ◽  
Degradation Process ◽  
Water Phase ◽  
Ionic Surfactants ◽  
Solvent Ratio ◽  
Nanoprecipitation Method

Nanoparticles were obtained by nanoprecipitation and by emulsion solvent evaporation (ESE) method. In the ESE method, the size of the particles depended on the type and concentration of surfactant (in the water phase) and the polymer concentration (in the organic phase). The best results were obtained with ionic surfactants, however, the use of such compounds may accelerate the degradation process of polymers. In the nanoprecipitation method, the ratio of solvent (methylene chloride) to non-solvent (hexane) has a significant influence on the particle size. The smallest particles were obtained with a solvent to non-solvent ratio of 1:150.

scholarly journals INFLUENCE OF POWDER CHARACTERISTICS ON THE SPREADABILITY OF PRE-ALLOYED TUNGSTEN- CARBIDE COBALT

2021 ◽  
Vol 32 (3) ◽  
pp. 284-289
Author(s):  
Preyin Govender ◽  
Deborah Clare Blaine ◽  
Natasha Sacks
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
Base Plate ◽  
Angle Of Repose ◽  
Critical Parameters ◽  
Powder Bed ◽  
Powder Characteristics ◽  
Particle Size And Shape ◽  
Spray Dried ◽  
Selection Of

With rising interest in additive manufacturing (AM) techniques, there is an increased focus on research that evaluates critical parameters that guide the selection of powders that are suitable for AM. One such parameter is a powder’s spreadability, described by metrics such as powder bed density and percentage coverage. This study focused on three spray-dried WC-Co powders (two 12 wt% and one 17 wt% Co) and evaluated the influence of typical powder characteristics, such as particle size and shape, apparent density, and flow rate, on their spreadability. It was found that particle size distribution influenced the powder spreadability. Larger particles hindered the even spreading of powder over the base plate, resulting in low powder bed density and percentage coverage. This also correlated with the powders’ apparent densities. The flow rate and angle of repose gave an indication of how cohesive the powders are. The more cohesive a powder, the poorer the spreadability, resulting in a lower powder bed density and percentage coverage.

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