Preparation, characterization and stability testing of cationic nanoemulsions

Cilj ovog diplomskog rada bio je razviti nanoemulziju U/V tipa stabiliziranu neionskim i ionskim surfaktantom te polielektrolitom. Nanoemulzije U/V tipa pripravljene su visokoenergetskom metodom mikrofluidizacije s Miglyolom 812 kao uljnom disperznom fazom. Pripravljenim nanoemulzijama mjerene su prosječna veličina kapljica, indeks polidisperznosti i zeta potencijal ovisno o rastućim udjelima lecitina S45, Cremophora EL i kitozana niske odnosno srednje molekulske mase. Nanoemulzije s najboljim svojstvima i stabilnošću bile su formulacije s 2,5% Migloyla 812, 0,05% lecitina S45, 0,25% Cremophora EL i 0,05% kitozana niske odnosno 0,1% kitozana srednje molekulske mase. Povećanjem udjela lecitina i Cremophora EL dolazi do smanjenja veličine kapljica sustava, dok u suprotnosti povećanje udjela kitozana rezultira većim kapljicama. Vrijednosti indeksa polidisperznosti nisu pokazale ovisnost o udjelu lecitina, dok rastućim udjelom Cremophora EL i kitozana PDI generalno raste. Rastućim udjelom lecitina postiže se sve negativniji zeta potencijal, no dodavanjem Cremophora EL taj negativni zeta potencijal opada. Dodatkom kitozana pak zeta potencijal se mijenja u pozitivne vrijednosti i raste sve većim udjelom kitozana. Sve razvojne formulacije s lecitinom i Cremophorom EL pokazale su stabilnost 30 dana nakon izrade. Konačne nanoemulzije koje su sadržavale još i kitozan pokazale su se nedovoljno stabilnima pri masenim udjelima kitozana niske molekulske mase od 0,1% i više te masenom udjelu kitozana srednje molekulske mase od 0,2% i više. Usporedbom rezultata mjerenja veličine kapljica, indeksa polidispoerznosti i zeta potencijala između nanoemulzija s kitozanom niske i nanoemulzija s kitozanom srednje molekulske mase nisu zabilježene značajne razlike u vrijednostima ovih parametara.The aim of this diploma thesis was to develop a nanoemulsion of O/W type stabilized by nonionic and ionic surfactant and polyelectrolyte. Nanoemulsions of O/W type were prepared using the high energy method of microfluidisation with Miglyol 812 as the oily dispersed phase. The prepared nanoemulsions were subjected to measurments of thier average droplet size, polydispersity index and zeta potential depending on the rising mass fraction of lecithin S45, Cremophor EL and low, as well as medium molecular weight chitosan. The final nanoemulsions with the best properties and stability were formulations containing 2,5% Miglyol 812, 0,05% lecithin S45, 0,25% Cremophor EL and 0,05% low and 0,1% medium molecular weight chitosan respectively. By increasing the fraction of lecithin and Cremophor EL, droplet size of the system decreases, while, on the contrary, increasing the fraction of chitosan results in bigger droplets. The values of the polydispersity index did not show dependence on the lecithin share, while the growing share of Cremophor EL and chitosan generally increases the PDI values. Zeta potential gets more and more negative with the increase of lecithin share, but by adding Cremophor EL that negative zeta potential diminishes and approaches zero. The addition of chitosan sees the shift of zeta potential into positive values that grow with an increasing share of chitosan. All of the developmental formulations containing lecithin and Cremophor EL expressed stability thirty days after their preparation. The final nanoemulsions with low molecular weight chitosan share of 0,1% and above and medium molecular weight chitosan share of 0,2% and above were found to be not stable enough during the same period of thirty days. Comparison of the results of average droplet size, polydispersity index and zeta potential measurments between low and medium molecular weight chitosan nanoemulsions did not show significant differences in the values of these parameters