Background: Many substances are used to increase the viscosity of eye drops and reduce their surface tension. Their function is to prolong the persistence of the product on the surface of the eyeball and to increase the bioavailability of the pharmacologically active ingredient.
Objectives: To investigate the surface tension of substances added to the eye drops, with the main aim of modulating properties of the preparation.
Material And Methods: Five substances contained in solutions proposed for the development of eye drops were studied: sodium hyaluronate macromolecular (H-Na W), sodium hyaluronate ultramolecular (H-Na UM), hyaluronic acid 4% (K-H), methylcellulose (MC), and polyacrylic acid (PA). The main method was to study the surface tension using the du Noüy ring tensiometer.
Results: The research presented in this paper shows the various effects of different eye drop ingredients on the surface tension of the solutions. The surface tension values of PA solutions are in the range of 48.89-56.03 mN/m, of MC in the range of 68.94-89.32 mN/m, of K-H 54.54-65.66 mN/m, of H-Na UM 67.18-70.97 mN/m, and of H-Na W 67.09-71.73 mN/m.
Conclusions: The use of different polymers affects the surface tension of model solutions proposed for use in ophthalmic preparations. Compounds containing carboxyl groups and anionic polymers have a similar effect on reducing the surface tension of the solution as classical surfactant compounds.
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http://dx.doi.org/10.17219/pim/175643 | DOI Listing |
J Colloid Interface Sci
December 2024
School of Health Sciences, Stopford Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK.
Hypothesis: Nanoscale characterisation of the self-associated species formed by amphiphilic pharmaceuticals in aqueous solution carries relevance across their entire journey from development through to manufacture - relevant, therefore, not only as regards formulation of the drug products as medicines, but also potentially relevant to their bioavailability, activity, and clinical side effects. Such knowledge and understanding, however, can only be fully secured by applying a range of experimental and theoretical methodologies.
Experiments: Herein, we apply a synergistic combination of solubility, surface tension, SANS, NMR and UV spectroscopic studies, together with MD simulation and QM calculations, to investigate the meso-structures of propranolol hydrochloride aggregates in bulk aqueous solutions, at concentrations spanning 2.
Food Chem
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KU Leuven, Department of Microbial and Molecular Systems, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001 Leuven, Belgium. Electronic address:
Due to compositional differences, the mouthfeel of non-alcoholic beers (NABs) is considered inferior to that of alcoholic beers (ABs). Carbonation properties are a key sensation regarding mouthfeel. This study quantified the amount of bubbles in ABs (n = 10) and NABs (n = 9), ranging from 3.
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December 2024
Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan.
We investigated oscillatory motion of a camphor disk floating on water containing 5 mM hexylethylenediaminium trifluoroacetate (HHexen-TFA) as an ionic liquid (IL). The frequency of the oscillatory motion increased with increasing concentrations of the transition metal ions Cu and Ni but was insensitive to Na, Ca, and Mg, the typical metal ions in the water phase. The surface tension of the water phase containing 5 mM HHexen-TFA also increased with increasing concentrations of Cu and Ni but was insensitive to Na, Ca, and Mg.
View Article and Find Full Text PDFLangmuir
December 2024
School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, United Kingdom.
To form nonspherical emulsion droplets, the interfacial tension driving droplet sphericity must be overcome. This can be achieved through interfacial particle jamming; however, careful control of particle coverage is required. In this work, we present a scalable novel batch process to form nonspherical particle-stabilized emulsions.
View Article and Find Full Text PDFSci Total Environ
December 2024
Instituto de Investigaciones para la Industria Química (INIQUI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de Salta (UNSa), Argentina; Facultad de Ciencias Naturales, UNSa, Argentina. Electronic address:
In this study, five strains previously isolated from black liquor (BL) and vinasse (V) were tested to assess the most promising regarding its capacity of biosurfactant production. For that, four factorial designs of two factors at two levels (2) were run for each strain. Selected factors were the production time and the composition media, while the surface tension reduction and optical density were the responses variables.
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