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Pharmaceutics
July 2022
Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, 90123 Palermo, Italy.
In the present study, gastro-resistant microparticles (MPs) were produced using the spray-drying technique as controlled-release systems for some model liposoluble vitamins, including retinyl-palmitate, retinyl-acetate, β-carotene, cholecalciferol and α-tocopherol. The gastroprotective action of three different gastro-resistant excipients, the anionic methacrylic copolymer (Eudraguard Biotic, E1207), the cellulose acetate phthalate (CAP) and whey proteins (WPs), was compared. The latter was used to produce a novel delivery system manufactured with only food-derived components, such as milk, and showed several improvements over the two synthetic gastro-resistant agents.
View Article and Find Full Text PDFIntravenous injection of caseine hydrolysate, hydrolysin or amino-peptide to dogs was not attended by any substantial changes in the activity of retinylpalmitate- and retinyl-acetate-hydrolase in the intestinal juice, as compared to the juice secreted on an empty stomach. The mutual relation of these enzymes activity in the intestinal juice and jejunal wall was dissimilar, which testifies to their different localization in the intestinal tissues.
View Article and Find Full Text PDFHydrolysis of retinylpalmitate and retinylacetate was studied in rat blood, liver tissue, intestine, testes, placenta and embryonic liver. The retinylpalmitate hydrolase activity was observed only in walls of small intestine and, less distinctly, - in liver tissue of some animals. Retinylpalmitate was hydrolyzed in rat liver very slowly, that was determined apparently by the metabolic requirements of the organism.
View Article and Find Full Text PDFThe retinol and retinylpalmitate content along with the retinylacetate and retinylpalmitate-hydrolase in the blood of the portal vein and in the peripheral blood from the superficial vein of the hind limb of dogs was determined in chronic experiments before and 1, 2, 3 and 4 hours after administration of the vitamin A preparations into the small intestine fistula. The introduction of an oily retinylacetate solution into the fistula was attended both by an increase of the retinylpalmitate content in the blood plasma and the appearance therein of the retinyl-palmitat-hydrolase activity. Introduction of an aquous-colloidal solution of retinyl-palmitate caused a rise in the latter's content in the blood but was not accompanied by the appearance of the retinyl-palmitate-hydrolase activity.
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