Formulation, characterization, and <i>in vitro</i> release of topical nanoemulsion containing prednisolone-derived corticosteroid

Prednisolone-derived corticosteroid (PDC) has anti-inflammatory activity in ocular administration. However, drug administration to the eye is extremely difficult due to the complex structure of the eye. Because of the ability of the eye to retain the drug and its physiology, the bioavailability of drugs applied to the eye is very low. One of the methods to overcome bioavailability problem is to formulate the drug as a nanoemulsion (NE). NEs are thermodynamically stable, colloidal drug delivery systems. They have small globule size and high surface area. These properties give them the ability to cross the biological membrane and increase the therapeutic efficacy of the drug molecule. The high energy method was used to create an NE eye drop formulation containing PDC, and the effects of changing homogenization processes on NE formation were investigated. After deciding on the optimum formulation; characterization, assay, and <i>in vitro</i> release studies were performed, and the stability of the formulation was followed for 12 months. The optimum formulation selected initially had 126.6 ± 40.12 nm and 99.9 ± 1.2% PDC, it had 125.4 ± 41.20 nm and 99.29 ± 1.3% PDC after 12 months in 25 °C 40% RH conditions. Cytotoxicity studies have shown no significant cytotoxic effects in NE-containing PDC. The preparation and optimization of topical NE formulations containing PDC for ocular inflammation treatment were achieved. The developed formulation was stable for 12 months and no toxic effect was found in cell culture studies. This formulation could be useful as an alternative to PDC for ocular applications.