Abstract
Purpose :
To develop a non-preserved OTC Dry Eye Drop resulting in improvements for both treatment of patient dry eye symptoms and support of general corneal health. In-vitro experimentation focused on addressing: (1) efficient eye movement lubrication, (2) tear film easily spreading over the cornea, and (3) healthy cornea. Based upon initial in-vitro experimentation, Test Formulations (TFs) were selected that represented formulation approaches determined to positively address these health benefits. In particular; natural oils (rich in unsaturated fatty acids), hyaluronate, antioxidant vitamins, an osmoprotectant, and metabolically important endogenous tear fluid amino acids were included as ingredients in Selected TFs to address health benefit (3).
Methods :
Lubricity was assessed by measuring the transit time for a “sled” pulled by a constant force to move across a hydrophobic surface covered by test material (TM). Spreadability was assessed by measuring the weight of TM needed to completely cover the surface of a polystyrene (hydrophobic) petri dish. Membrane stabilization and water loss studies were conducted by mixing TFs with bovine red blood cells (RBCs), subjecting the mixture to light and heat (34○C), and then measuring the amount of intact RBCs and water loss.
Results :
The Lubricity Ratio of Selected TFs (n=7) varied from 1.067 to 1.451 and Comparator Marketed Products (CMPs, n=7) varied from 0.631 to 1.251. Higher Lubricity Ratio values indicate a greater reduction in the friction of a moving object (e.g., eye lid) over a stationary surface such as the cornea (benefit 1). The Spreadability Ratio of the Selected TFs (n=7) varied from 1.37 to 1.78 and CMPs (n=7) ranged from 0.94 to 1.50. Higher Spreadability Ratio values indicate that the test material can more easily cover a hydrophobic surface such as the cornea (benefit 2). Membrane stabilization studies indicated that flaxseed oil in the TF resulted in more RBCs being lysed (p≤0.05) than when castor oil or 4 other natural oils were used (benefit 3). When compared to normal saline; two natural oils lowered (p≤0.05) water evaporative loss, with a lower water loss trend noted for castor and flaxseed oils (benefit 3).
Conclusions :
The ingredients were formulated to display the desirable in-vitro characteristics of increased lubricity, ability to easily spread, and greater membrane stabilization while incorporating ingredients beneficial to corneal health.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.