Abstract
Purpose :
Meibomian gland dysfunction is characterized by poor quality, quantity and integrity of the tear film due to lipid insufficiency. Targeted delivery of polar phospholipids to supplement the meibum using nanoemulsions can improve tear film function, stability and lipid layer thickness. This preclinical study aimed to evaluate a novel nano droplet-lipid based artificial tear product containing hydroxypropyl-guar, anionic phospholipid, mineral oil, and the demulcent propylene glycol in vitro and ex-vivo corneal epithelium models.
Methods :
The % protection provided by the lipid nanoemulsion solution to human corneal epithelial cell lines from desiccation using the cell proliferation assay was compared to controls. Sodium fluorescein permeability was measured to determine whether these formulations can promote recovery of barrier function following damage. A lubricity assessment using a coefficient of friction experiment with pericardium tissue was also conducted. Solutions were tested by measuring effects of 5, 6-carboxyfluorescein permeability on the corneal epithelium of intact rabbit eyes.
Results :
Compared to vehicle (n=38), nanoemulsion-treated cells (n=33) showed significantly greater hydration protection against desiccation (0% vs 39%, p<0.05). Compared to vehicle (n=63), cell protection by surface retention after rinse was also greater in treated cells (n=73) (0% vs 33%; p<0.05). After 48-hours in normal medium, barrier function of nanoemulsion-treated cells post benzalkonium chloride (BAC) treatment returned to control levels relative to the vehicle. The mean±SD fluorescence values (relative fluorescence units) 30 minutes after BAC exposure were 3.11±0.4 in vehicle and 2.66±0.2 with nanoemulsion (p<0.05, n=18). Fluorescein permeability (ng CF/g) in rabbit corneas following treatment with nanoemulsion formulation relative to BAC exposure was (9.57 vs 22.59; p<0.05; n=5). The nanoemulsion formulation also demonstrated greater lubricity among pericardial tissue samples, (2 min after application), than vehicle (p<0.05, n=3).
Conclusions :
The lipid nanoemulsion based artificial tear formulation provided more effective moisture retention, protection, and improved cell barrier function than vehicle. This nanoemulsion artificial tear formulation may be beneficial in reducing ocular surface damage while replenishing the lipid layer of the tear film in patients with dry eye.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.