Colloidal Dispersion Stability: Kinetic Modeling of Agglomeration and Aggregation

Gonzatti, Guilherme Kilpp; Netz, Paulo Augusto; Fiel, Luana Almeida; Pohlmann, Adriana Raffin

doi:10.5935/0103-5053.20140290

Cited by 3 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Various methods of analysis are used for kinetic studies of dispersion systems [ 43 , 44 ]. The advantages of the method of laser diffraction of light over other similar methods (nephelometry, turbidimetry) made it possible to apply it to kinetic studies of dissolution.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

et al. 2021

View full text Add to dashboard Cite

The most important task in the design of dosage forms is to modify the pharmaceutical substances structure in order to increase solubilization, targeted delivery, controlled rate of drug administration, and its bioavailability. Screening—laboratory (in vitro) or computer (in silico)—as a procedure for selecting a prototype for the design of a drug molecule, involves several years of research and significant costs. Among a large number of solvents and diluents (alcohol, ether, oils, glycerol, Vaseline) used in the pharmaceutical industry for the manufacture of drugs water finds the greatest application. This is because all biological reactions (reactions in living systems) take place in water and distribution of the fluid in the body and the substances found within is critical for the maintenance of intracellular and extracellular functions. Modern studies in the field of the stable isotopic compositions of natural water and its structure and properties make it possible to use isotopic transformations of the water to improve the pharmacokinetic properties of medicinal substances without previous structural modification. It is known that by replacing any of the atoms in the reacting substance molecule with its isotope, it is possible to record changes in the reactivity, which are expressed as a change in the reaction rate constant, i.e., in the manifestation of the kinetic isotope effect (KIE). The article presents the results of studies on the effect of the kinetic isotope effect of a solvent—water—on increasing the solubility and dissolution rate constants of poorly soluble drugs using laser diffraction spectroscopy. The results of the studies can be successfully implemented in pharmaceutical practice to overcome the poor solubility of medicinal substances of classes II and IV, according to the biopharmaceutical classification system (BCS), in water for pharmaceutical purposes by performing its preliminary and safe isotopic modification.

show abstract

Section: Resultsmentioning

confidence: 99%

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

et al. 2021

View full text Add to dashboard Cite

show abstract

“…As the particle size of a suspension sample decreases down to the nanoscale, the surface to volume ratio and the surface energy increase. In the same way, NCPs tend to be inherently thermodynamically unstable and thus subjected to physical instability resulting in an aggregation and/or fusion of particles [ 42 ]. As a consequence, an increase in particle size and particle size distribution (PSD) is of paramount importance, particularly when NCPs are intended to the intravenous route.…”

Section: Instability Of Nanocapsules In Aqueous Mediamentioning

confidence: 99%

Lyophilization of Nanocapsules: Instability Sources, Formulation and Process Parameters

Degobert

Aydin

2021

Pharmaceutics

View full text Add to dashboard Cite

Polymeric nanocapsules have gained more and more interest in the medical sciences. Their core-shell structure offers numerous advantages, especially regarding their use as drug delivery systems. This review begins by presenting the different intrinsic sources of the instability of nanocapsules. The physical and chemical potential instabilities of nanocapsules reduce their shelf-life and constitute a barrier to their clinical use and to their commercialization. To overcome these issues, lyophilization is often used as a process of choice in the pharmaceutical industry especially when labile compounds are used. The state of the art of lyophilization nanocapsules is reviewed. The formulation properties and the process parameters are discussed for a complete understanding of their impact on the stability and storage of the final dried product. To assess the quality of the dried product, various characterization methods are also discussed.

show abstract

“…The thermal resistances of the SiO 2 /PAMPS nanoparticles were investigated in terms of the dispersion stability of the nanoparticles in salt solution at high temperature because the temperature of shale formations is higher than that of Earth's surface. 25 For drilling in shale formations, the concentration of salt is usually lower than 20 wt %. The temperature of shale formations that are drilled increases with increasing depth in the Earth's interior by a temperature gradient of 30 °C/km.…”

Section: Industrial and Engineering Chemistry Researchmentioning

confidence: 99%

Poly(2-acrylamide-2-methylpropanesulfonic acid)-Modified SiO₂ Nanoparticles for Water-Based Muds

Wu¹,

Wang²,

Zhu³

et al. 2016

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

We report the fabrication of poly(2-acrylamide-2-methylpropanesulfonic acid) modified SiO2 (SiO2/PAMPS) nanoparticles as plugging agents in water-based muds (WBMs). SiO2/PAMPS nanoparticles were prepared by the copolymerization of 3-methacryloxypropyltrimethoxysilane-functionalized SiO2 nanoparticles and 2-acrylamide-2-methylpropanesulfonic acid. These SiO2/PAMPS nanoparticles were found to exhibit excellent salt tolerance, thermal stability, and good compatibilities with polymeric additives commonly used in WBMs. The plugging capabilities of the nanoparticles were tested with filter cakes on a high-temperature, high-pressure filtration press. The results indicated that SiO2/PAMPS nanoparticles can effectively block the nanopores in filter cake. In addition, WBMs containing SiO2/PAMPS nanoparticles were found to exhibit excellent plugging properties both at ambient temperature and at 80 °C, demonstrating that these nanoparticles are promising plugging agents in WBMs for drilling in shale formations.

show abstract

Colloidal Dispersion Stability: Kinetic Modeling of Agglomeration and Aggregation

Cited by 3 publications

References 0 publications

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

Lyophilization of Nanocapsules: Instability Sources, Formulation and Process Parameters

Poly(2-acrylamide-2-methylpropanesulfonic acid)-Modified SiO₂ Nanoparticles for Water-Based Muds

Contact Info

Product

Resources

About

Colloidal Dispersion Stability: Kinetic Modeling of Agglomeration and Aggregation

Cited by 3 publications

References 0 publications

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

Lyophilization of Nanocapsules: Instability Sources, Formulation and Process Parameters

Poly(2-acrylamide-2-methylpropanesulfonic acid)-Modified SiO2 Nanoparticles for Water-Based Muds

Contact Info

Product

Resources

About

Poly(2-acrylamide-2-methylpropanesulfonic acid)-Modified SiO₂ Nanoparticles for Water-Based Muds