Self-microemulsifying drug delivery system

Mikroemulzije su se u proteklih nekoliko godina pojavile kao novi dozirni oblik kojim se omogućuje povećanje apsorpcije djelatne tvari u organizam. To su termodinamički stabilni, optički izotropni sustavi sastavljeni od ulja, vode, surfaktanata i kosurfaktanata. Zbog postojanja hidrofilnih i lipofilnih domena pokazuju poboljšanu topljivost djelatne tvari. Prema strukturi dijele se na mikroemulzije ulja u vodi, mikroemulzije vode u ulju te bikontinuirane strukture. U eksperimentalnom su istraživanju formirane samoorganizirajuće mikroemulzije s uklopljenim dronedaron-hidrokloridom. Dronedaron-hidroklorid otopljen je u etanolu koji je uklonjen isparavanjem u rotacijskom isparivaču i vakuumskom sušioniku. Korištena su dva stabilizatora, Kolliphor EL i Kolliphor RH40. In vitro metodom ispitana je brzina oslobađanja dronedaron-hidroklorida iz mikroemulzija. Promjena koncentracije dronedarona određena je pomoću UV/Vis spektrofotometra mjerenjem apsorbancije te su dobiveni profili oslobađanja dronedaron-hidroklorida. Mikrografijama je potvrđeno da dodatkom pripremljenog sustava u fosfatni pufer nastaju mikroemulzije. In vitro metoda ispitivanja pokazala je izuzetno brzo oslobađanje dronedaron-hidroklorida iz mikroemulzija, već 90 % nakon 10 minuta.In last few years, microemulsions have been recognized as new alternative dosage form which allows increase in the absorption of active substance. They are thermodynamically stable, optically isotropic systems of oil, water, surfactants and cosurfactants. Due to the existence of hydrophilic and lipophilic domains better solubility of active substances is possible. Structurally, they are divided into oil in water, water in oil and bicontinuous microemulsions. Self-microemulsifying drug delivery systems containing dronedarone hidrochloride were prepared in this study. Dronedarone hydrochloride was dissolved in ethanol and then removed by evaporation in rotational evaporator and vacuum dryer. Two stabilizers were used, Kolliphor EL i Kolliphor RH40. In vitro method was used to determine the release rate of dronedarone hydrochloride from microemulsions. The change of dronedarone concentration was determined measuring the absorbance by UV/Vis spectrophotometer. Also, dronedarone hydrochloride dissolution profiles were obtained. Micrographs confirmed self-formation of microemulsions when prepared mixtures were added into phosphate buffer. In vitro method showed instant release of dronedarone hydrochloride from microemulsions, 90% after 10 minutes