3D printed system using ex vivo porcine eye globes to investigate intracorneal absorption of dexpanthenol from contact lens care solution and eye drops

Reduction of the use of animal models in research is encouraged for the sake of animal wellbeing. However, available <i>in vitro</i> models in the specific case of topical ocular delivery/penetration studies are often oversimplified by the use of excised corneal or scleral tissue and the frequent lack of dynamic barriers such as the lacrimal outwash. This is why we have developed our novel <i>ex vivo</i> porcine eye globe 3D printed laboratory setup with simulated tear flow, using enucleated porcine eyes. This setup was employed to investigate the penetration of a common topical formulation excipient Dexpanthenol (Dxp). First, Dxp deposition in soft contact lenses following usage of SOLOCARE AQUA® care solution was quantified by UHPLC-MS/MS. The subsequent penetration into corneal tissue and aqueous humour of Dxp from SOLOCARE AQUA® care solution treated contact lenses was compared to that following application of eye drop solutions Bepanthen® and Siccaprotect®, containing equivalent Dxp concentrations. The results showed that the Dxp concentration in the anterior segment was three-fold higher after application of the Dxp-containing eye drops as compared to contact lens application. Given that Dxp uptake was greater following the application of the marketed eye drops, this confirmed the safety of the Dxp-containing contact lens care solution. This research demonstrates how topical delivery studies on the ocular surface can be simulated in our novel <i>ex vivo</i> porcine eye globe model without the need to sacrifice laboratory animals<b>.</b>