Examinando por Autor "Zepeda, Katherine"
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Ítem Evaluation of ceftiofur-PHBV microparticles in rats(Dove Medical Press Ltd., 2014-05) Vilos, Cristian; Constandil, Luis; Rodas, Paula I.; Cantin, Mario; Zepeda, Katherine; Herrera, Natalia; Velasquez, Luis A.Despite the high number of antibiotics used for the treatment of infectious disease in animals, the development of slow release formulations presents a significant challenge, particu larly in using novel biomaterials with low cost. In this report, we studied the pharmacokinetics, toxicity, and therapeutic activity of ceftiofur–PHBV (ceftiofur–poly(3-hydroxybutyrate-co 3-hydroxyvalerate)) in rats. The pharmacokinetic study demonstrated a sustained release of ceftiofur into the bloodstream, with detectable levels over the minimum inhibitory concentration for at least 17 days after a single intramuscular injection of ceftiofur–PHBV (10 mg/kg weight). In addition, the toxicological evaluation of biochemical, hematological, and coagulation blood parameters at the therapeutic dose demonstrated the safety of ceftiofur–PHBV, with no adverse effects. In addition, ceftiofur–PHBV exhibited a therapeutic effect for a longer time period than the nonencapsulated ceftiofur in rats challenged with Salmonella Typhimurium. The slow release of ceftiofur from the ceftiofur–PHBV, its low toxicity in the blood parameters evaluated, and the efficacy in the rats infected with Salmonella Typhimurium make ceftiofur–PHBV a strong candidate for biotechnological applications in the veterinary industry.Ítem Polymeric Nanoparticles in Dermocosmetic(Sociedad Chilena de Anatomía, 2015) Bahamonde-Norambuena, D.; Molina-Pereira, A.; Cantin, Mario; Muñoz, M.; Zepeda, Katherine; Vilos, CristianRecent advances in the fields of biomaterials and nanotechnology have allowed the development of advanced nanoparticles for biomedical applications. Despite a vast number of nanostructures such as liposomes, solidlipid nanocapsules, polymeric and hybrid lipidpolymer nanoparticles have been studied as carriers for drug delivery for different pathologies with remarkable promising results; the use of polymeric nanoparticles in dermocosmetic still has not been widely explored. The evolution of cosmetic into the care skin and dermatology represents novel technological challenges. Also, the increasing knowledge about normal skin physiology and advances in nanotechnology provide an attractive environment for the creation of innovative dermocosmetic formulations. In this work, we discuss the state of the art of polymeric nanoparticles formulated for dermocosmetics, its mechanisms of action, and diffusion into the skin.Ítem Preclinical development and in vivo efficacy of ceftiofur-PLGA microparticles(Public Library of Science, 2015-04) Vilos, Cristian; Velasquez, Luis A.; Rodas, Paula I.; Zepeda, Katherine; Bong, Soung-Jae; Herrera, Natalia; Cantin, Mario; Simon, Felipe; Constandil, LuisDrug delivery systems based on polymeric microparticles represent an interesting field of development for the treatment of several infectious diseases for humans and animals. In this work, we developed PLGA microparticles loaded with ceftiofur (PLGA-cef), a third-generation cephalosporin that is used exclusively used in animals. PLGA-cef was prepared by the double emulsion w/o/w method, and exhibited a diameter in the range of 1.5-2.2 μm, and a negative ζ potential in the range of -35 to -55 mV. The loading yield of PLGA-cef was ∼7% and encapsulation efficiency was approximately 40%. The pharmacokinetic study demonstrated a sustained release profile of ceftiofur for 20 days. PLGA-cef administrated in a single dose was more effective than ceftiofur non-encapsulated in rats challenged with S. Typhimurium. The in vivo toxicological evaluation showed that PLGA-cef did not affect the blood biochemical, hematological and hemostasis parameters. Overall, the PLGA-cef showed slow in vivo release profile, high antibacterial efficacy, and low toxicity. The results obtained supports the safe application of PLGA-cef as sustained release platform in the veterinary industry. © 2015 Vilos et al.