Alejandro Melero

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.

Crosslinked hyaluronic acid dermal fillers are widely used for non-permanent aesthetic enhancement, offering safe and effective solutions for facial volume restoration. Specific formulations are designed for targeted facial regions, with highly crosslinked hydrogels often recommended for volumizing areas such as the jawline, chin, and cheeks due to their structural properties. While elasticity and viscosity are commonly evaluated, broader comparative analyses remain limited. In this study, we assess five commercially available HA-based fillers with similar HA concentrations, all optimised for volume enhancement. Alongside widely used reference products, we evaluate BtHCROSS 2%^®, a novel formulation not previously compared to established fillers. We examined the degree of chemical modification, mechanical viscoelastic behaviour, susceptibility to enzymatic degradation by hyaluronidase, and injection force. While all tested fillers are suitable for volume restoration, BtHCROSS 2%^® demonstrates a distinctive combination of mechanical adaptability, structural support, enzymatic resistance, and low injection force, making it a versatile option for practitioners.