34 KB227 KB30 KB199820252009Bešter-Rogač, MarijaGašperlin, MirjanaRozman, BrankaZvonar, Alenkaštevilka:1letnik:56str. 131-138ISSN:1318-0207COBISSID:2523761URN:URN:NBN:SI:doc-6IXBWLGOenSlovensko kemijsko društvoActa chimica slovenicadrugfizikalne lastnostimikroemulzijemikrostrukturasproščanje zdravilzdravilaThe influence of microstructure on celecoxib release from a pharmaceutically applicable system: Mygliol 812/Labrasol/Plurol oleiquer/water mixtures|Structural transformations were investigated in unloaded and celecoxib-loaded microemulsions on a dilution line containing, initially, 12 wt. % of Mygliol 812r and 88 wt. % of the surfactant (Labrasolr)/co-surfactant (Plurol Oleiquer), 4:1 wt. % mixture. Electrical conductivity, viscosity, surface tension and density measurements revealed that two structural transitions takeplace along the dilution line studied. At ~27 wt. % of water the oil-continuous (w/o) system converted to a bicontinuous microemulsion and a transition to a water-continuous (o/w) microemulsion followed at ~45 wt. % of water. After incorporation of celecoxib at 1 wt. % concentration the microemulsion remained stable and no change in its microstructure was observed. Celecoxib release was then measured for each type of microemulsion. It was shown to be influenced by the microstructure and solubilization capacity of the system, and can, to a certain extent, be predicted. Stability testing of celecoxib-loaded microemulsions revealed that they are stable over 90 days storage at 40 °CProučevali smo spremembo notranje strukture mikroemulzij, ki nastanejo po razredčevanju začetne zmesi sestavljene iz 12 % (m/m) Mygliola 812 ç in 88 % (m/m) emulgatorja (Labrasol ç) ter koemulgatorja (Plurol Oleique ç) v razmerju 4:1. Rezultati meritev električne prevodnosti, viskoznosti, površinskenapetosti ter gostote nakazujejo, da vzdolž preučevane razredčitvene premice potekata dva strukturna prehoda; pri !-27 % (m/m) vode mikroemulzija s kontinuirano oljno fazo (v/o) najprej preide v bikontinuiran sistem, nakar sledi prehod slednjega v mikroemulzijo s kontinuirano vodno fazo(o/v) pri !-45 % (m/m) vode. Vgradnja 1 % (m/m) celekoksiba ni vplivala nastabilnost in mikrostrukturo nastalega sistema. Proučevali smo tudi hitrost in obseg sproščanja celekoksiba iz posameznih mikroemulzijskih struktur ter ugotovili, da je sproščanje odvisno tako od mikrostrukture kot od solubilizacijske kapacitete sistema in ga je v določeni meri mogoče napovedati. Potrdili smo tudi stabilnost mikroemulzij s celekoksibom med 90 dnevnim shranjevanjem pri 40CTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaSlovensko kemijsko društvo