Eye drop formulations allowing topical treatment of retinal pathologies have long been sought as alternatives to intravitreal administration. This study aimed to assess whether a novel nanostructured microemulsions system (NaMESys) could be usefully employed to deliver sorafenib to the retina following topical instillation. NaMESys carrying 0.3% sorafenib (NaMESys-SOR) proved to be cytocompatible in vitro on rabbit corneal cells, and well-tolerated following b.i.d. ocular administration to rabbits during a 3-month study. In rats subject to retinal ischemia-reperfusion, NaMESys-SOR significantly inhibited retinal expression of tumor necrosis factor-alpha (TNFα, 20.7%) and inducible nitric oxide synthase (iNos, 87.3%) mRNAs in comparison to controls. Similarly, in streptozotocin-induced diabetic rats, NaMESys-SOR inhibited retinal expression of nuclear factor kappa B (NFκB), TNFα, insulin like growth factor 1 (IGF1), IGF1 receptor (IGF1R), vascular endothelial growth factor receptor 1 (VEGFR1) and 2 (VEGFR2) mRNAs by three-fold on average compared to controls. Furthermore, a reduction in TNFα, VEGFR1 and VEGFR2 protein expression was observed by western blot. Moreover, in mice subject to laser-induced choroidal neovascularization, NaMESys-SOR significantly inhibited neovascular lesions by 54%. In conclusion, NaMESys-SOR was shown to be a well-tolerated ophthalmic formulation able to deliver effective amounts of sorafenib to the retina, reducing proinflammatory and pro-angiogenic mediators in reliable models of proliferative retinopathies. These findings warrant further investigations on the full therapeutic potential of NaMESys-SOR eye drops, aiming to address unmet needs in the pharmacotherapy of retinal neovascular diseases.

Background/Objectives: Retinal ganglion cell (RGC) protection represents an unmet need in glaucoma. This study assessed the neuroprotective, antioxidant, and anti-inflammatory effect of a new nutraceutical formulation named Epicolin, based on citicoline, homotaurine, epigallocatechin-3-gallate, forskolin, and vitamins, through in vitro and in vivo studies. Methods: The neuroprotective effect of Epicolin or its single components, and Epicolin compared to an untreated control and two marketed formulations [Formulation G (FG) and N (FN)], was evaluated in neuroblastoma cells (SH-SY5Y) challenged with staurosporine. The antioxidant potential and the scavenging activity of Epicolin compared to the untreated control, and FG and FN, was evaluated in SH-SY5Y cells and through oxygen radical absorbance capacity acellular assay, respectively. Moreover, the protective effect against hypoxic damage was evaluated in Muller cells (MIO-M1) subjected to hypoxia. The efficacy of Epicolin was also evaluated in DBA/2J glaucomatous mice through the use of a pattern electroretinogram (PERG), immunostaining, and real-time PCR. Results: Among the nutraceutical formulations tested, only Epicolin showed a significant neuroprotective effect on SH-SY5Y attributable to the synergistic action of its single ingredients. As for antioxidant and scavenging activity, Epicolin showed a higher efficacy compared to FG and FN. Furthermore, Epicolin showed the same protective effect on MIO-M1 cells reducing HIF-1α expression. Finally, Epicolin treatment on DBA/2J mice protected the RGCs from loss of function, as demonstrated by PERG analysis, and attenuated their death by enhancing brain-derived neurotrophic factor (BDNF) and reducing interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) expression. Conclusions: Epicolin, due to its neuroprotective, antioxidant, and anti-inflammatory properties, represents a promising potential treatment for glaucoma.

Background/Objectives: A novel ophthalmic formulation, XanterDES, containing 0.2% xanthan gum and 0.025% desonide sodium phosphate (DES), was developed to alleviate ocular surface discomfort and irritation. This study aimed to evaluate its pharmacodynamic properties and to characterize its rheological behavior and mucoadhesive characteristics, compared to another formulation containing 0.2% hyaluronic acid and 0.001% hydrocortisone (HYD). Methods: A rabbit (New Zealand White) model of LPS-induced uveitis was used to test different concentrations of DES on ocular markers of inflammation. The efficacy of XanterDES and HYD on induced dry eye was evaluated by assessing tear volume and corneal damage in C57BL/6 mice exposed to a controlled environmental chamber. The rheological and mucoadhesive properties of XanterDES and HYD were assessed using a HAAKE RheoStress RS600 rheometer and a TA-XT2 texture analyzer, respectively. Results: In the uveitis model, unlike DES 0.25%, a low concentration of 0.025% DES showed a significant inhibitory activity localized to the eye surface and effectively reduced corneal edema. In the dry eye model, XanterDES demonstrated superior efficacy compared to HYD, effectively preventing both tear volume reduction and corneal damage. XanterDES also demonstrated pseudoplastic and enhanced mucoadhesive properties compared to HYD. Conclusions: The ancillary anti-inflammatory effects of a low dose of DES combined with the biophysical properties of xanthan gum are supportive of a favorable therapeutic profile, promoting the maintenance or restoration of ocular surface homeostasis while minimizing the risk of adverse effects typically associated with standard-dose corticosteroids. The comparison with another low-dose corticosteroid highlights the superiority of XanterDES in pharmacodynamic and biophysical performance.