Study on the applicability of dynamic light scattering (DLS) to microemulsions including supercritical carbon dioxide-swollen micelles

Cadogan, Shane P.; Hahn, Christian; Rausch, Michael H.; Fröba, Andreas P.

doi:10.1016/j.jcis.2017.03.111

Cited by 23 publications

(7 citation statements)

References 42 publications

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“…Detection Scheme without and with Reference Light. Previous DLS studies for microemulsions 25,26 have shown that for colloidal systems, the scattered light intensities may not be large enough to fulfill the assumption of a homodyne detection scheme. Applying the corresponding working equations in the form of eq 2 or 3 can result in deviations by up to a factor of 2 for the obtained diffusion coefficients.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The capability of polarized DLS to provide rotational diffusion coefficients in solely this scattering geometry is a major advantage compared with depolarized DLS, which requires a broad variation of angles under which scattered light is analyzed. Since one cannot assume a priori a homodyne detection scheme for the analysis of scattered light originating from colloid systems, , results obtained for the gold nanorod dispersions without a local oscillator are compared with those for heterodyne conditions. Here, the scattered light is superimposed coherently with much stronger reference light.…”

Section: Introductionmentioning

confidence: 99%

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Translational and Rotational Diffusion Coefficients of Gold Nanorods Dispersed in Mixtures of Water and Glycerol by Polarized Dynamic Light Scattering

et al. 2019

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Polarized dynamic light scattering (DLS) gives access to orientation-averaged translational and rotational diffusion coefficients of anisotropic particles dispersed in fluids in a single experiment. As the combination of both diffusivities contains information on the morphology of the particles, their simultaneous and accurate measurement for the same sample and thermodynamic state is beneficial for particle characterization. For nontransparent model suspensions of gold nanorods in water and water–glycerol mixtures, a scattering geometry in reflection direction was realized, which minimizes multiple scattering and allows using low laser powers to avoid laser heating. Furthermore, a heterodyne detection scheme was guaranteed by superimposing much stronger reference light to the scattered light. This ensures an unambiguous data evaluation and reduces the uncertainties for the rotational and the translational diffusivity, where the latter is accessible with smaller uncertainty. For the water-based suspensions, both diffusivities agree well with the stick hydrodynamic theory for rods and show an Andrade-type behavior in the studied temperature range from 271 to 323 K. The measured results for both diffusivities, particularly for the rotational diffusivity, indicate a breakdown of the stick boundary conditions for dynamic viscosities larger than 4 mPa·s.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Translational and Rotational Diffusion Coefficients of Gold Nanorods Dispersed in Mixtures of Water and Glycerol by Polarized Dynamic Light Scattering

et al. 2019

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“…The zeta potential of the internal phase cells of emulsions as well as the particulate capsules was measured using the Zetasizer Malvern NanoS disposition. Thus, by determining electrophoretic mobility, and, on the basis of the Smoluchowski equations, the value of the zeta potential was established [ 56 ].

where η —environment viscosity of dispersion; μ —electrophoretic mobility; ε —dielectric constant of the dispersion environment.…”

Section: Methodsmentioning

confidence: 99%

Drug-Loaded Polymeric Particulated Systems for Ophthalmic Drugs Release

et al. 2022

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Drug delivery to the anterior or posterior segments of the eye is a major challenge due to the protection barriers and removal mechanisms associated with the unique anatomical and physiological nature of the ocular system. The paper presents the preparation and characterization of drug-loaded polymeric particulated systems based on pre-emulsion coated with biodegradable polymers. Low molecular weight biopolymers (chitosan, sodium hyaluronate and heparin sodium) were selected due to their ability to attach polymer chains to the surface of the growing system. The particulated systems with dimensions of 190–270 nm and a zeta potential varying from −37 mV to +24 mV depending on the biopolymer charges have been obtained. Current studies show that particles release drugs (dexamethasone/pilocarpine/bevacizumab) in a safe and effective manner, maintaining therapeutic concentration for a longer period of time. An extensive modeling study was performed in order to evaluate the drug release profile from the prepared systems. In a multifractal paradigm of motion, nonlinear behaviors of a drug delivery system are analyzed in the fractal theory of motion, in order to correlate the drug structure with polymer. Then, the functionality of a SL(2R) type ”hidden symmetry” implies, through a Riccati type gauge, different ”synchronization modes” (period doubling, damped oscillations, quasi-periodicity and intermittency) during the drug release process. Among these, a special mode of Kink type, better reflects the empirical data. The fractal study indicated more complex interactions between the angiogenesis inhibitor Bevacizumab and polymeric structure.

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“…The average value of droplet size and the polydispersity index (PDI) of the formulated microemulsions were measured by applying the dynamic light scattering (DLS) technique, using Zetasizer Nano ZS particle size analyzer (Malvern, Malvern, UK) [15]. Briefly, 20 µL of prepared microemulsions were diluted with 980 µL distilled water in a disposable plastic cuvette and placed in the path of light that measures DLS.…”

Section: Physical Characterization Of Microemulsionsmentioning

confidence: 99%

Preparation of Ophthalmic Microemulsions Containing Lithuanian Royal Jelly and Their Biopharmaceutical Evaluation

et al. 2021

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Royal jelly is a natural substance secreted by worker honeybees that possesses antioxidant, anti-inflammatory, and other biological activities. The purpose of this study was to formulate microemulsions with incorporated Lithuanian royal jelly for possible ophthalmic delivery and to evaluate the quality of the microemulsions in vitro. The oil in water type microemulsions were prepared by the oil titration method, incorporating royal jelly, surfactant, co-surfactant, oil, and water. Physicochemical characteristics of the microemulsions and the quantity of 10-hydroxy-2-decenoic acid released in vitro were assessed. The in vitro assessment of prepared microemulsions formulations was performed with the Statens Seruminstitut rabbit cornea (SIRC) cell culture model. The results revealed that the droplet size of all microemulsion formulations was 67.88–124.2 nm and the polydispersity index was lower than 0.180. In the in vitro release study, the release of 10-hydroxy-2-decenoic acid depended on the amount of royal jelly incorporated and on the ratio of surfactant and co-surfactant in formulations. The in vitro tests with the SIRC cell culture line have shown that all formulations were found non-irritating.

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Study on the applicability of dynamic light scattering (DLS) to microemulsions including supercritical carbon dioxide-swollen micelles

Cited by 23 publications

References 42 publications

Translational and Rotational Diffusion Coefficients of Gold Nanorods Dispersed in Mixtures of Water and Glycerol by Polarized Dynamic Light Scattering

Translational and Rotational Diffusion Coefficients of Gold Nanorods Dispersed in Mixtures of Water and Glycerol by Polarized Dynamic Light Scattering

Drug-Loaded Polymeric Particulated Systems for Ophthalmic Drugs Release

Preparation of Ophthalmic Microemulsions Containing Lithuanian Royal Jelly and Their Biopharmaceutical Evaluation

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