Research has indicated that there is a correlation between the molecular weight of hyaluronan or hyaluronic acid (HA) and its biocompatibility/biological functions with high molecular weight HA showing many biological benefits. The purpose of this research was to characterize and compare the molecular weights, molecular weight distributions, and concentrations of HA present in a series of commercially available HA-containing ophthalmic products.
On-line size-exclusion chromatography with triple detection (SEC-TD) was used to determine the molecular weights and concentration of HA in commercially available products, including marketed contact lens multipurpose solutions and contact lens packaging solutions. Eleven commercially available HA-containing ophthalmic products were characterized by SEC-TD.
The weight-average molecular weights of the products tested ranged from 155,000 Daltons (Da) to 1,400,000 Da, the number-average molecular weight of the products ranged from 99,000 to 927,000 Da, and the concentration of HA ranged from 0.003 to 0.15%.
A wide range of HA molecular weights and concentrations were found in the 11 ophthalmic products characterized in the present study. This study is the first reported to characterize HA molecular weights and concentrations in various marketed HA-containing ophthalmic products. Future investigation of the effect of low molecular weight HA on eye is required.