The physical stability of two types of MCT-emulsions made by different technologies - physical mixture vs. structured lipids - was studied as a function of storage time and temperature. Particle size analysis, zeta potential and dynamic surface tension measurements were carried out to evaluate the possible changes in the kinetic stability of the emulsions. Our results indicate that the physical mixture technology of MCT-emulsions resulted in impaired physicochemical stability compared to the ones containing structured triglycerides. In the case of structured lipids, both medium and long chain fatty acids can be found in one triglyceride molecule, leading to a favorable interfacial location of structured triglycerides. Besides the advantageous metabolic effects of structured triglycerides, their application is recommended to improve the physical stability of TPN admixtures.
"In our previous studies the droplet size stability of all-in-one nutritive mixtures containing different fat emulsions were studied. Authors concluded that droplet stability of MCT/LCT lipids surpassed the pure LCT  and the SMOF-lipid was more stable than that of MCT/LCT . In our present study we broadened the range of lipids with olive-oil containing emulsion. "
[Show abstract][Hide abstract] ABSTRACT: TPN infusions are usually administered during a treatment period of 10-24 hours per day due to the metabolic capacity of the liver. During this time interval physicochemically stable TPN solution (emulsion) is needed for the treatment. The purpose of the present study was to examine how the kinetic stability features of ready-made total parenteral nutrition admixtures containing olive oil and soybean oil will change under the usage-modeling 24-hour application with and without overdose Ca2+.
Particle size analysis and zeta potential measurements were carried out to evaluate the possible changes in the kinetic stability of the emulsions.
Our results indicate that in two of the four mixtures bimodal droplet-size distribution figures were detected and appearance of fat particles over 5 μm can not be disclosed. The tendency for separation of large diameter droplets in the two types of oil-based emulsion systems was different. In case of soybean containing emulsion second peak of droplets appeared in the bottom of the container in contrast to the olive oil containing emulsions where the second peak appeared in the surface layer. Interestingly this phenomenon is independent of calcium-content.
From therapeutic point the emulsions of the bigger droplets containing upper layer are safer because the potentially dangerous big droplets could remain in the infusion bag after the administration.
[Show abstract][Hide abstract] ABSTRACT: In the design of electrostatic lenses, a rapid and reliable method of determining electron trajectories is required. This paper describes a demountable vacuum system incorporating an electron gun, deflection plates, clyindrical lenses and a pair of phosphor coated mesh structures. The various parts are assembled on heavy bases which rest on precision ground and graduated glass rods. A vacuum sealed push-rod permits adjusting the relative positions of the lenses during testing. The electron beam passes through the parallel phosphor coated meshes and the lighted spots are observed by means of a cathodometer to determine beam landing angle. The complete device thus provides a tool for measuring not only the effects of changing the potentials of electrostatic lens elements but of changing their relative positions as well during a single test. The complete system is called an "electron optical bench" and also includes a simple 9 × 9 dot pattern generator. The pattern of dots viewed on the phosphor meshes will quickly reveal aberration due to lens distortion.
Electron Devices Meeting, 1961 Internationa; 02/1961
[Show abstract][Hide abstract] ABSTRACT: The purpose of the present study was to examine how the colloid stability features of o/w parenteral nutrition emulsions made with SMOFlipid (lipid emulsion based on soybean oil, medium chain triglycerides, olive oil and fish oil) will change in the presence of high concentration of calcium and glucose if usual micronutrients are also present, according to the needs of the clinical nutrition patient. Particle size analysis, zeta potential, dynamic surface tension measurements and light microscopic screening were carried out to evaluate the possible changes in the kinetic stability of the emulsions. Our results indicate that the higher glucose concentration of 15 or 20% could not compensate the emulsion-destabilizing effect of higher (5 mM) calcium concentration even in the presence of a modern fat emulsion. Therefore calcium demand of undernourished patient requiring 5 mM or higher final Ca²⁺ content in nutrient solution should be supplemented in another way.
Journal of pharmaceutical and biomedical analysis 05/2011; 56(2):159-64. DOI:10.1016/j.jpba.2011.05.002 · 2.98 Impact Factor
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