Engineered PVA-tamarind gum-based biocomposite for sustained ophthalmic delivery of moxifloxacin: Effect of nanocellulose on physicochemical, mechanoelectrical and permeation kinetics.

Widely used polysaccharide-based films in ophthalmic drug delivery have major limitations of inadequate mechanical strength, poor electrical conductivity, and insufficient ocular drug permeability. Moxifloxacin (MFX) biocomposite film of adequate mechanoelectrical properties was developed for sustained ophthalmic drug delivery. Nanocellulose (NC) incorporated (2.5, 5.0, 7.5, and 10.0 %) PVA-tamarind gum-based moxifloxacin composite was prepared using solvent casting method. The addition of NC improved the mechanical properties of the film, demonstrating its ability to strengthen the structure. Stress relaxation (SR) of the film has been augmented (64.67±7.55 to 73.15±0.34 %) due to increased content of NC (0 to 10 %) respectively. Film containing 5 % NC showed the critical edge of tensile strength (11.9±0.39 MPa), and also the threshold limit of electrical conductivity (4.5*10⁷ Ω). The same film exhibited continued drug release as well as erosion-controlled sustained ocular permeation (pH 7.4) and revealed the highest antibacterial activity (ZOI of disc diffusion, cm) with Pseudomonas aeruginosa (4.63±0.15) and Staphylococcus aureus (4.30±0.26) of MFX (≈224 μg). Notably, incorporating NC produced non-irritating and safe for corneal delivery as confirmed by the Draize model test. Our findings suggested that the NC-containing PVA-tamarind gum-based composite film holds a promising approach for sustained ophthalmic delivery of MFX.