Characterization of a New Phospholipid Containing Nanoemulsion Lubricant Eye Drop for Dry Eye

Abstract

Purpose : Lipid-based artificial tear products are designed to reduce tear evaporation by restoration of the deficient tear lipid layer. Hydroxypropyl Guar (HPG) has been shown in the presence of demulcents to support ocular surface protection. This work summarizes the performance of a phospholipid (PL) and HPG-containing nanoemulsion lubricant eye drop on biological surfaces.

Methods : Biological performance was measured as the ability of formulations to (a) maintain viability, (b) provide protection from desiccation and (c) improve surface lubrication. Two marketed lipid-containing dry eye products (Refresh Optive Advanced-OA and Soothe XP-XP) were tested alongside a HPG-based nanoemulsion. Growth media and saline were used as controls for the cell viability/desiccation and lubrication experiments. Cells were incubated with test solutions for 30 minutes and then desiccated for 0 or 5 min at 37°C; 45% humidity. An alamarBlue assay was used to determine % viability and % protection. Surface lubrication was assessed by measuring friction on bovine pericardium tissue. Data from cell viability/desiccation experiment was analyzed using ANOVA (one-way, Welch’s, p<0.05) and for lubrication studies using paired t-test (p≤0.05).

Results : Cell viability (percent of media control) and protection from desiccation stress (percent non-desiccated control) were calculated. The PL+HPG containing nanoemulsion eye drop demonstrated significantly greater cell viability than OA and XP (81%, vs. 45%, and 31% respectively, p<0.05) and better cellular protection from desiccation stress than OA and XP (28% vs 5% and 4% respectively, p<0.05). Surface friction in pericardial tissues demonstrated greater lubrication after exposure of the formulation and persistence of lubrication after removal of the formulation (p≤0.05).

Conclusions : The PL+HPG-containing nanoemulsion lubricant solution showed greater cell viability, protection against desiccation and improved surface lubrication compared to other lipid containing artificial tears. These data indicate that the phospholipid containing nanoemulsion eye drop may provide long lasting lubrication and surface protection in the eye.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.