Translational Evaluation Of A Phmb 5 Ppm And Cross-Linked Hyaluronic Acid Ophthalmic Solution: Antimicrobial, Antifungal, And Anti-Adhesion Activity

To evaluate the antimicrobial, antifungal, and anti-adhesive efficacy of a polyhexamethylene biguanide (PHMB) 5 ppm and cross-linked hyaluronic acid (HA-CL) ophthalmic solution across in vitro, ex vivo, and in vivo models, assessing its potential role in ocular surface antisepsis and infection prevention.

University of Bari, Italy

Antimicrobial activity was assessed through time-kill assays against Staphylococcus aureus (MSSA and MRSA), Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli, comparing the test solution with povidone-iodine 0.66% and ozonized oil-based drops.
Antifungal activity was evaluated against Candida albicans, Aspergillus fumigatus, and Aspergillus flavus.

Anti-adhesion activity against Acanthamoeba castellanii was studied using reconstructed human corneal epithelium (HCE) under both co-incubation (prophylactic simulation) and post-adhesion paradigms, with scanning electron microscopy (SEM) characterization.

In vivo efficacy was evaluated in patients undergoing cataract surgery, with conjunctival swabs. 

The solution demonstrated rapid bactericidal activity, achieving complete bacterial eradication within minutes across all tested strains, with superior performance against P. aeruginosa and E. coli compared to comparators.

Fungistatic activity was observed against C. albicans and A. fumigatus, while limited activity was detected against A. flavus.

In the Acanthamoeba model, simultaneous application reduced trophozoite adhesion by 33%, while post-adhesion treatment reduced adhesion by 52% (p < 0.05). SEM confirmed decreased surface colonization and biofilm density.

In vivo, a 97% mean reduction in conjunctival bacterial load was observed (CrI 82–99%), with a 99.9% probability of bacterial reduction in initially colonized eyes.

This PHMB 5 ppm and HA-CL ophthalmic formulation demonstrates broad-spectrum antimicrobial activity, antifungal potential, and significant inhibition of early Acanthamoeba adhesion, supported by clinical reduction of conjunctival flora.

The combined antiseptic and mucoadhesive platform may represent a safe and effective strategy for perioperative prophylaxis and infection risk reduction in high-risk ocular surface conditions.