The development of topical ophthalmic formulations is a major challenge due to the low solubility of ophthalmic active substances and the anatomical and physiological barriers of the eye. One solution to this problem may be development of nanoemulsions, which is a relatively new and insufficiently investigated drug delivery system. For the purposes of this diploma thesis, cationic O/ W nanoemulsions were prepared, which included the stearylamine as positively charged surfactant, and Kolliphor EL as surfactant which additionally sterically stabilized them. Positive charge on the surface of the oil droplets with the active ingredient, allows cationic nanoemulsions to improve drug retention, due to electrostatic interactions with the negatively charged surface of the eye. In this diploma thesis the nanoemulsions with stearylamine were prepared using a microfluidizer and then tested for their physiochemical properties and biocompatibility. With the increase in the content of stearylamine in nanoemulsions increases the size, index of polydispersity, zeta-potentials and pH values. Likewise, the values of the examined parameters were within the expected limits for ophthalmic formulations. In order to test stability of prepared nanoemulsions, measurements of the same parameters were repeated after 30 days of storage of nanoemulsion at 4ºC, and the results showed that the nanoemulsions maintained their stability and did not show a significant change in homogeneity compared to the measurements that were made on the day of preparation. Nanoemulsions were shown to be biocompatable using the multilayer in vitro model of human corneal epithelium, using a HCE-T cell line grown on Transwell® plates, and the viability of the model determined with a colorimetric MTT test was approximately 90%. The results of this study indicate the potential of cationic nanoemulsion with stearylamine as a delivery system for drugs with low water solubility and which prolongs the drug retention on the surface of the eye without toxic effects.