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Nanotehnologija v zadnjih letih predstavlja eno izmed najbolj obetavnih področij v farmaciji. V farmacevtski nanotehnologiji je zelo aktualen razvoj nanodelcev, ki imajo pred konvencionalnimi dostavnimi sistemi številne prednosti. Običajno je produkt priprave nanodelcev disperzija, ki je dovzetna za različne vrste nestabilnosti. Posledično se za izboljšanje fizikalne in kemijske stabilnosti disperzij nanodelcev v zadnjih letih pospešeno proučujejo različni pristopi, med drugim tudi različne metode sušenja za pretvorbo disperzij nanodelcev v bolj stabilno suho obliko. Sušenje disperzij nanodelcev predstavlja velik tehnološki izziv. Z do danes razvitimi metodami sušenja je težko izdelati suh, nepraškast produkt ter sočasno preprečiti agregacijo nanodelcev med procesom sušenja in tako ohraniti njihovo prvotno velikost. Namen magistrske naloge je zato bil raziskati metodo elektrostatskega sukanja kot alternativno metodo za pretvorbo disperzij nanodelcev v suho obliko, ki bi premostila pomanjkljivosti do danes razvitih metod sušenja disperzij nanodelcev. Pred procesom elektrostatskega sukanja smo v etanolno (magnetni nanodelci) oz. vodno (polimerni nanodelci) disperzijo nanodelcev dodali polimera polietilenoksid in poloksamer 188 (v masnem razmerju 1:1), ki sta se v preteklosti že izkazala kot ustrezna za izdelavo suhega elektrostatsko sukanega produkta, ki se hitro dispergira v vodnem mediju. S sistematičnim spreminjanjem vsebnosti nanodelcev v disperziji smo določili največjo vsebnost nanodelcev, ki je še zagotavljala ustrezno redispergiranje le-teh iz suhega produkta. Tako smo v suh produkt uspešno vključili do 50 % (m/m) magnetnih nanodelcev oz. do 11 % (m/m) polimernih nanodelcev. Metoda elektrostatskega sukanja je za razliko od ostalih metod za sušenje disperzij nanodelcev omogočila izdelavo suhega produkta z nanodelci v nepraškasti obliki, kar je izrednega pomena z vidika varnosti pri rokovanju s posušenimi nanodelci. Suh produkt z magnetnimi nanodelci, ki smo ga izdelali iz etanolne disperzije, je bil v obliki nanovlaken, medtem ko suh produkt s polimernimi nanodelci, ki smo ga izdelali iz vodne disperzije nanodelcev, ni imel morfologije nanovlaken. Domnevamo, da je razlika v morfologiji produkta posledica vpliva disperznega medija na obnašanje polimerov med elektrostatskim sukanjem. Kljub razlikam v morfologiji je bilo iz obeh vrst suhih produktov mogoče z enostavnim stresanjem nanodelce pretvoriti nazaj v obliko disperzije. In recent years, nanotechnology has become one of the most promising fields in pharmacy. The development of nanoparticles is a hot topic in pharmaceutical nanotechnology because it offers a number of advantages over conventional drug delivery systems. Most nanoparticles are usually prepared in the form of dispersions, which are susceptible to vary instabilities. To improve the physical and chemical stability of nanoparticle dispersions, various approaches have been investigated in recent years, including the conversion of nanoparticle dispersions into a more stable dry form by different drying methods. Drying of nanoparticle dispersions is an important technological challenge. With the drying methods developed so far, it is difficult to produce a dry, non-powdered product, while preventing the aggregation of nanoparticles during the drying process and thus preserving their original size. Therefore, the aim of this Master's thesis was to investigate electrospinning as an alternative method for converting dispersions of nanoparticles into a dry form that would overcome the drawbacks of current drying methods. To successfully convert the aforementioned nanoparticle dispersions into a dry form, polyethylene oxide and poloxamer 188 (in a 1:1 weight ratio), which have been shown to be suitable for the preparation of a dry, easily dispersible product, were added to ethanol (magnetic nanoparticles) or aqueous (polymeric nanoparticles) dispersions before the electrospinning process. By systematic increase in the content of nanoparticles in the dry product, we determined the maximum content of nanoparticles in the dry product, which still ensured their adequate redispersion from the dry product. We successfully incorporated up to 50% (w/w) of magnetic nanoparticles or up to 11% (w/w) of polymer nanoparticles into dry product. Unlike other methods for drying nanoparticle dispersions, the electrospinning method allowed us to produce a dry product with nanoparticles in a non-powder form, which is important from a safety perspective. The dry product with magnetic nanoparticles, prepared from the ethanol dispersion, was in the form of nanofibers, whereas the dry product with polymeric nanoparticles prepared from the aqueous nanoparticle dispersions, was not. We assume that the difference in product morphology is due to the influence of the dispersion medium on the behaviour of the polymers during electrospinning. Despite the differences in morphology, the nanoparticles were successfully reconstituted from both types of dry product by simple shaking. |
