Effect of alcohols on micelle formation in aqueous solutions of ethoxylated nonyl-phenols

2008 ◽  
pp. 229-235 ◽  
Author(s):  
Zs. Bedő ◽  
E. Berecz ◽  
I. Lakatos ◽  
J. Lakatos-Szabó
Keyword(s):  
Aqueous Solutions ◽  
Micelle Formation

scholarly journals PECULARITIES OF MICELLE FORMATION OF PENTACYCLIC GLYCOSIDES IN AQUEOUS SOLUTIONS

2021 ◽  
Vol 64 (4) ◽  
pp. 26-33
Author(s):  
Natalia V. Mironenko ◽  
Irina V. Shkutina ◽  
Vladimir F. Selemenev
Keyword(s):  
Surface Tension ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Aqueous Solutions ◽  
Hydrodynamic Radius ◽  
Critical Concentration ◽  
Micelle Formation ◽  
Cylindrical Shape ◽  
Scattering Method ◽  
Dynamic Light Scattering Method

The regularities of changes in structural characteristics during the formation of associates in micellar aqueous solutions of triterpene saponins Quillaja Saponin and Sapindus Mukorossi are considered. The dependence of surface tension and adsorption on the concentration of an aqueous saponin solution is analyzed, and the values of surface activity and parameters of the adsorption layer are calculated. The average values of diffusion coefficients for spherical and cylindrical micelles are determined based on the measurement of the solution viscosity. The effect of the electrolyte solution on the surface tension and viscosity of glycoside solutions is studied: when the electrolyte is introduced into the saponin solution, the surface tension decreases, which leads to a shift in the critical concentration of micelle formation towards lower concentrations. The introduction of potassium chloride electrolyte reduces the degree of ionization and, as a result of suppressing the electroviscosity effect, leads to a decrease in the viscosity of the solution. The dynamic light scattering method is used to determine the size of glycoside aggregates. It is established that there are aggregates of several sizes in an aqueous solution of saponin. The size and shape of aggregates were calculated using the concepts of micelle packing parameters. In the region of very low concentrations of glycoside solutions, when approaching the critical concentration of micelle formation in the solution, there are spherical micelles. A further increase in the saponin concentration in the solution leads to a decrease in the content of structures with a hydrodynamic radius of 50-80 nm and the appearance of larger agglomerates with sizes greater than 100 nm. It was found that micelles acquire a less hydrated and more densely packed cylindrical shape in the concentration range of 1.7-2.6 mmol/dm3. Compaction of associates leads to an increase in the content of particles with a hydrodynamic radius of 150-250 nm and larger ones, and their presence predicts the appearance of larger agglomerates. Analyzing the data obtained using the dynamic light scattering method, it can be concluded that aggregates of several sizes co-exist in the volume of aqueous saponin solutions at certain concentrations.

scholarly journals Litogenolitic and solubility properties of products obtained from common ivy extract (Hederae helicis e folium) and medium of diversified polarity (εM)

2019 ◽  
Vol 65 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Elżbieta Nowak ◽  
Zbigniew Marczyński ◽  
Beata Skibska ◽  
Michał Jakub Nachajski ◽  
Jerzy Jambor ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Potential ◽  
Micelle Formation ◽  
Critical Micellar Concentration ◽  
Herbal Drugs ◽  
Efficacy And Safety ◽  
Micellar Solubilization ◽  
Hedera Helix ◽  
Inflammatory Drugs ◽  
Preformulation Studies

Summary Introduction: Common ivy (Hedera helix) is a plant used successfully in the treatment of various ailments. This is possible owing to the unique set of substances contained in it such as large amount of saponins, flavonoids, phenolic acids and phytosterols as well as polyacetylenes and coumarins. All these substances have been used in the production of cosmetic and medicinal preparations. Clinical trials on the efficacy and safety of dry ivy leaf extract have shown its high efficacy, comparable to synthetic medications, and better tolerance of herbal drugs. Objective: Investigations were performed on model ivy leaf (Hedera helix) extracts which were created using a medium of diversified polarity ( εM). Measurements of viscosity and surface activity on phase boundary were performed. During preformulation studies attention was drawn to the possibility of micellar solubilization of cholesterol and selected structures of nonsteroidal anti-inflammatory drugs (NSAIDs) – ketoprofen. Methods: Viscosity measurements of Extractum Hederae helicis e folium aqueous solutions and in 0.1 mol HCl were performed according to the Polish Standard with Ubbelohde dilution viscometer. The surface tension of aqueous solutions $- \Delta \gamma _{{\rm{sol}}}^{25}$ of Hederae helicis e folium extracts was determined according to the Polish Standard with stalagmometric method. Critical micellar concentration (cmc) was calculated. This enabled to evaluate the dependence $\Delta {\rm{G}}_{\rm{m}}^0 = 2.303$ RT×log cmc of the thermodynamic potential of micelle formation ( $\Delta {\rm{G}}_{\rm{m}}^0$ ). Results: It has been confirmed in the conducted comparative studies that aqueous solutions of Extr. Hederae helicis e folium created with maltodextrin as well as with SiO2 – maltodextrin result in micellar solubilization. The increase of granulometric size of cholesterol particle to Ø 1.60 mm decreased the amount of solubilized cholesterol but solubility preferences of the extracts were maintained. Conclusions: Model extracts produced from Hederae helicis e folium with diversified polarity of the extraction medium (water – ethanol) are characterized by appropriate solubility of the components which results not only from the presence of chlorophyll and its derivatives in the extract but also from the technique used for spray drying of the extract.

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