Dual drug loaded dissolvable annular microneedle patch to treat bacterial conjunctivitis

The effective management of anterior segment ocular diseases such as bacterial conjunctivitis is limited by poor corneal permeability and rapid precorneal drug loss. Although microneedle-based ocular drug administration overcomes these barriers, the reported microneedle array designs show obstruction of vision and potential for alteration in the visual pathway reducing their clinical translation. Here, we report a novel annular microneedle patch (AMP) design containing gatifloxacin and prednisolone combination that maintains central corneal transparency, enabling safe limbal-scleral placement without visual obstruction against bacterial conjunctivitis. Dissolvable AMP was fabricated using polyvinyl alcohol and polyvinylpyrrolidone by micromolding technique. The AMP features 171 pyramidal microneedles (577.5 ± 17 µm length and 284 ± 8 µm base width) arranged in two concentric rings to achieve peri-limbal application while minimizing direct corneal contact. Mechanical tests confirmed sufficient compression strength (0.43 ± 0.04 N per microneedle) and lower ocular insertion force (0.17 ± 0.02 N), with complete dissolution within 60 s. The ex vivo goat eye studies showed significantly (P < 0.05) greater drug retention in the anterior tissues compared with eye drop formulation. A 3D printed applicator was developed for standardized insertion, ensuring consistent dosing and user-friendly application. Dual-drug AMP patches incorporating prednisolone and gatifloxacin showed enhanced corneal and scleral drug deposition, resulting in reduced Staphylococcus aureus load in the ex vivo goat eye and in vivo rabbit eye models. In vivo bacterial conjunctivitis model, AMP application led to faster resolution of conjunctival inflammation, improved stromal integrity, and restored corneal clarity relative to commercial formulation. Overall, AMP showed a minimally invasive, vision preserving ocular delivery system offering superior bioavailability and therapeutic efficacy of gatifloxacin and prednisolone in bacterial conjunctivitis model.