Enhanced Ocular Retention and Anti-Allergic Efficacy of a Novel HA–Ectoine–CMC Eye Drop for Dry Eye Disease Management

Dry eye disease (DED) is a multifactorial ocular surface disorder that significantly affects vision and quality of life. While artificial tears are the standard first-line therapy, their effectiveness is limited by the complex pathophysiology of DED. This study evaluated DayDrop® Triple Action, a novel formulation combining hyaluronic acid (HA), ectoine, and carboxymethylcellulose (CMC), designed to enhance tear film stability and ocular surface protection. Physicochemical and rheological properties were assessed, including viscosity, pseudoplasticity, and viscoelastic behaviour under dynamic conditions, along with ectoine release over 24 h. An in vitro allergic conjunctivitis model using conjunctival fibroblasts exposed to a pro-allergic cytokine cocktail was employed to examine immunomodulatory effects. DayDrop® Triple Action demonstrated high viscosity with pronounced pseudoplasticity and stable viscoelasticity, supporting improved mucoadhesion. The formulation provided sustained ectoine release and exhibited a positive immunomodulatory effect, likely linked to ectoine’s preferential hydration mechanism, which stabilizes membranes and reduces inflammatory signalling. These findings suggest that DayDrop® Triple Action integrates viscoelastic optimization, osmoprotection, and targeted anti-inflammatory action, offering a promising non-pharmacological strategy for managing DED and allergic ocular surface disorders.