Topical drug administration is the most widely used and commonly accepted treatment for many eye diseases. However, the bioavailability of topical ophthalmic drugs is low due to the highly effective protective mechanisms of the eye. As nanoemulsions can overcome these barriers, their application is increasingly being explored and particular emphasis is placed on cationic nanoemulsions that interact with the negatively charged surface of corneal epithelial cells and thus enhance drug absorption. As part of this thesis, cationic nanoemulsions with stearylamine as a positive charge carrier were examined. In order to determine the concentration of stearylamine that provides the properties most suitable for ophthalmic administration, the key physicochemical properties of nanoemulsions that affect their clinical performance including droplet size, polydispersity index, zeta potential, pH, formulation viscosity profile as a function of applied shear force, and surface tension were examined.It was found that all nanoemulsions show the characteristics of Newtonian systems. Low formulation viscosity enables dosing accuracy and ease of eye-drop administration. A nanoemulsion with 0.05 % (m/m) stearylamine has a pH value most suitable for ophthalmic administration. Stearylamine reduces the surface tension of the nanoemulsion, and by measurement it was found that 0.05 % stearylamine in the sample is a concentration limit that will not cause discomfort when applied. The zeta-potential of nanoemulsions increases in proportion with the increase of stearylamine concentration, and after incubation with the dispersion of mucin, values decreased. All samples show acceptable droplet sizes (⁓100 nm) and polydispersity indexes (PDI < 0.2). An increase in the size of stearylamine-containing nanoemulsions after incubation with mucin dispersion was observed. Changes were most evident in the 0.05 % (m/m) and 0.1 % (m/m) stearylamine samples so it was concluded that these samples have the strongest mucoadhesive properties. Considering the results of the physico-chemical and mucoadhesive tests, the formulation with 0.05 % (m/m) stearylamine stood out as the most optimal for ophthalmic use.