Browsing by Subject "tocopherol"

Organogels refer to gels whose liquid phase is composed of an organic solvent instead of water. Compared to hydrogels it is estimated that oil based organogels, alias oleogels, are able to improve the solubility and bioavailability of the poorly water-soluble drugs and also to promote the stability of the easily water-degradable drugs. Furthermore, it has been estimated that compared to fluid oil based products organogels are able, especially in veterinary medicine, to facilitate the administration of the drugs and other nutritive substances by guaranteeing more precise and more stable administration platform. The purpose of this work was to develop and to optimize the composition and the manufacturing process of the organogel based nutritional product for pets. Fish oil and solid active pharmaceutical ingredients were used as active components of the nutritional product but in addition for operating as a source of fatty acids fish oil also functioned as a liquid phase of the organogel formulation. In this work the fish oils were thickened with colloidal silicon dioxide. In addition to the silica different surface active agents; krill oil, lecithin or tocopherol; were also added to some of the formulations in order to enhance the gelation property of the colloidal silicon dioxide. Systematic design of experiments was utilized in the planning of the organogel formulation test series. Two different silicon dioxide grades and seven different surface active agents were used in this work. The three-dimensional structure of the organogel samples were examined by Cryo-TEM. The rheological properties of the organogel formulations were determined by dynamic rotation rheometer one week and 3 months after the preparation of the organogel samples. On the basis of the observations that were done in this work, certain levels of krill oil and lecithin grades Phosal® 35 SB, Phosal® 53 MCT and Phosal® 75 SA were able to enhance the gelation property of the silica-fish oil mixtures compared to the formulations that contained only plain silica or silica-tocopherol mixtures. Especially krill oil was found to be able to enhance the thickening effect of the silica-fish oil mixtures even when small concentrations and low shear rates were used whereas either high silica contents or high shear rates were needed to thicken the pure fish oil-silica mixtures. Although krill oil and lecithin grades Phosal® 35 SB, Phosal® 53 MCT and Phosal® 75 SA were, in certain concentration levels, able to enhance the thickening effect of the silica-based fish oil mixtures the predemands of the paste-like consistency, solidity and 2 years stability time were not fulfilled as desired. On the basis of the observations that were done in the pre-tests, it is however possible that either by using different krill oil and fish oil combinations or by using higher shear methods it could be possible to form the desired, stiff, paste-like, stable organogels at least with the help of krill oil and colloidal silicon dioxide.