Aragona P, Simmons PA, Wang H, Wang T. Physicochemical Properties of Hyaluronic Acid-Based Lubricant Eye Drops.
Transl Vis Sci Technol 2019;
8:2. [PMID:
31695963 PMCID:
PMC6827422 DOI:
10.1167/tvst.8.6.2]
[Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 08/01/2019] [Indexed: 12/19/2022] Open
Abstract
PURPOSE
To assess the physicochemical properties of hyaluronic acid (HA)-based artificial tears.
METHODS
The average molecular weight (MW) and polydispersion index (PDI) of HA in 18 commercially available artificial tears were determined by light scattering/high-performance liquid chromatography. Osmolality, pH, viscosity, and sodium concentration were determined using an osmometer, pH meter, rheometer, and inductively coupled plasma mass spectrometer, respectively.
RESULTS
The MW of HA varied considerably between formulations. The PDI was >2.0 in two formulations (2.28 and 4.94), suggesting the presence of a copolymer and/or HA size variability. Three formulations exhibited viscosity exceeding the blur threshold at different shear rates. Viscosity at low shear rates was generally highest in formulations containing high-MW HA. Correlations were found between observed viscosity and a predictive/calculated value, except for four copolymer-containing formulations, and osmolality (range, 154-335 mOsm/kg) and sodium concentration (range, 22-183 mM), with two exceptions. Compared with organic osmolytes, adding sodium decreased viscosity, particularly at lower shear rates.
CONCLUSIONS
In the context of the literature, our findings suggest that for most patients with dry eye disease, the ideal HA-based artificial tear should include high-MW HA with a low PDI and exhibit enhanced viscosity at low shear rate (without exceeding the blur threshold). The inclusion of synergistic copolymers and a low sodium concentration may increase viscosity, but whether any of these physicochemical properties or correlations can predict clinical efficacy will require further investigation.
TRANSLATIONAL RELEVANCE
Understanding the properties of HA-based artificial tears will support the development of unique formulations that target specific ocular surface conditions.
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