Hydrodynamic Compatibility of Hyaluronic Acid and Tamarind Seed Polysaccharide as Ocular Mucin Supplements

Abstract

Hyaluronic acid (HA) has been commonly used in eyedrop formulations due to its viscous lubricating properties even at low concentration, acting as a supplement for ocular mucin (principally MUC5AC) which diminishes with aging in a condition known as Keratoconjunctivitis sicca or “dry eye”. A difficulty has been its short residence time on ocular surfaces due to ocular clearance mechanisms which remove the polysaccharide almost immediately. To prolong its retention time, tamarind seed gum polysaccharide (TSP) is mixed as a helper biopolymer with HA. Here we look at the hydrodynamic characteristics of HA and TSP (weight average molar mass Mw and viscosity ) and then explore the compatibility of these polymers, including the possibility of potentially harmful aggregation effects. The research is based on a novel combination of three methods: sedimentation velocity in the analytical ultracentrifuge (SV-AUC), size-exclusion chromatography coupled to multiangle light scattering (SEC-MALS) and capillary viscometry. HA and TSP were found to have ) kg/mol and ) kg/mol respectively, and and ml/g, respectively. The structure of HA ranges from a rodlike molecule at lower molar masses changing to a random coil for Mw > 800 kg/mol, based on the Mark–Houwink–Kuhn–Sakurada (MHKS) coefficient. TSP, by contrast, is a random coil across the range of molar masses. For the mixed HA-TSP systems, SEC-MALS indicates a weak interaction. However, sedimentation coefficient (s) distributions obtained from SV-AUC measurements together with intrinsic viscosity demonstrated no evidence of any significant aggregation phenomenon, reassuring in terms of eye-drop formulation technology involving these substances.

The effect of tamarind seed polysaccharidecontaining eye drop in dry eye syndrome: Results of an interventional, comparative, clinical study

“…The combination of hyaluronic acid with TSP enhanced the residence time of the solution [17] . These 2 polysaccharides are compatible in solutions [17] , and a synergistic interaction has been demonstrated between them [18]. The current clinical study found increased tear stability and production 2 weeks after Xiloial ® eye drop instillation.…”

“…Hyaluronic acid, which has viscous lubricating properties, has been used as a supplement for ocular mucin [17] and is included in the Xiloial ® eye drop formulation. The combination of hyaluronic acid with TSP enhanced the residence time of the solution [17] .…”

“…Hyaluronic acid, which has viscous lubricating properties, has been used as a supplement for ocular mucin [17] and is included in the Xiloial ® eye drop formulation. The combination of hyaluronic acid with TSP enhanced the residence time of the solution [17] . These 2 polysaccharides are compatible in solutions [17] , and a synergistic interaction has been demonstrated between them [18].…”

Hyaluronic Acid and Galacto-Xyloglucan Eyedrop Efficacy in Young-Adult Oral Contraceptive Users of Childbearing Age

“…Furthermore, in our study, we invasively measured BUT with fluorescein, as in the study by Barabino et al [ 41 ], and it was significantly higher in the HA-GX group and lower in the HA group. The reason for these results could be the similarity among the structures of galacto-xyloglucan, the tamarind seed polysaccharide (TSP), and the mucin MUC1 present in the conjunctival epithelium [ 26 , 42 ]. There have been studies showing how the combination of HA-GX is effective in the treatment of dry eye due to its mucoadhesive and mucomimetic properties [ 24 , 43 , 44 ].…”