3D-printed setup for ocular drug delivery evaluation on ex vivo porcine whole eye.

Reaching the back of the eye without invasive intraocular injections is still nowadays challenging. Luckily, the nanotechnology can help in improving the effectiveness and the patient compliance and, ultimately, the therapeutic success rate. The development and characterization of ophthalmic (nano)formulations benefit from the implementation of ex vivo models, that allow to disclose the formulation behaviour once in contact with biological tissues and consequently its optimization. Ex vivo ocular models help to minimize the number of promising formulations deserving to be investigated in in vivo animal models, in compliance with the 3Rs principle, and therefore their availability is of paramount importance. In this research work, we present a 3D-printed reusable device designed to be used in a whole porcine eye bulbs setup comparing it with the Franz-cell. The device, produced by a Masked Stereolithography Apparatus, consists of two components, the Ocudonor, acting as a donor chamber for the formulation, and the Ocutainer, which simultaneously contains up to three ocular bulbs. The porcine eye setup was validated using a dexamethasone-loaded nanostructured lipid carriers for periocular administration and intended for the treatment of the posterior segment of the eye. The porcine whole eye model proved capable of preserving eye structure integrity for at least 18 hours and, unlike the Franz-cell, enabled the evaluation of the drug's lateral diffusion along the eye bulb.