RESUMEN
Mesoporous silica nanoparticles (MSNPs) were synthesized and loaded with metformin hydrochloride (Metf), its adsorption has studied at different concentrations and pHs, optimal adsorption conditions were determined. Hybrid MSNPs-Metf were mixed with chitosan to compress them and form quasi-spherical pellets, were coated with five chitosan layers as a barrier to prolong metformin release. It showed that this pellet is useful for metformin controlled release since drug over time was significantly delayed by the chitosan coating and then, as metformin is electrostatically linked to MSNPs, it also controls the release of drug, releasing 170â¯mg after 17â¯h of exposure at pHâ¯1.2. When pH is >1.2, metformin release was significantly prolonged. Since 170â¯mg is 21% of a 850-mg metformin dose and previous studies report that 90% of metformin is recovered as unchanged drug in urine after 12â¯h of metformin intakes. These results suggest that MSNPs-Metf pellets, coated with chitosan, are an option to avoid excessive metformin ingest.
Asunto(s)
Portadores de Fármacos/química , Hipoglucemiantes/química , Metformina/química , Nanopartículas/química , Dióxido de Silicio/química , Preparaciones de Acción Retardada/química , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Liberación de Fármacos , PorosidadRESUMEN
A natural and biocompatible extract of garlic as a support, decorated with silver nanoparticles, is a proposal to generate an effective antifungal agent against dermatophytes at low concentrations. Silver nanoparticles (AgNPs) with a diameter of 26±7â nm were synthesized and their antimycotic activity was examined against Trichophyton rubrum (T. rubrum), inhibiting 94 % of growth at a concentration of 0.08â mg ml-1 . Allium sativum (garlic) extract was also obtained (AsExt), and its MIC was 0.04â mg ml-1 . To increase the antifungal capacity of those systems, AsExt was decorated with AgNPs, obtaining AsExt-AgNPs. Using an AsExt concentration of 0.04â mg ml-1 in independent experiments with concentrations from 0.01 to 0.08â mg ml-1 of AgNPs, it was possible to inhibit T. rubrum at all AgNPs concentrations; it proves a synergistic effect between AgNPs and AsExt. Even if 1 % of the minimum inhibitory concentration of AsExt (0.0004â mg ml-1 ) is used, it was possible to inhibit T. rubrum at all concentrations of AgNPs, demonstrating the successful antimycotic activity potentiation when combining AsExt and AgNPs.