Soluble ocular insert of brinzolamide and timolol maleate: in-vitro , ex-vivo and in-vivo characterization

Aims The present study aimed to formulate and evaluate a novel transparent and soluble ocular insert containing a fixed-dose combination of Brinzolamide (210 µg) and Timolol maleate (105 µg).Materials and methods The soluble ocular inserts were formulated using hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) as film-forming polymers. Optimization of the parameters was done using a D-optimal design.Results and conclusions The optimized soluble ocular inserts were found to be transparent, homogeneous, flexible and demonstrated acceptable surface pH (7.21 ± 0.12), bioadhesive strength (11.88 ± 0.89 g), and tensile strength (1.016 ± 0.13 MPa). In-vitro studies demonstrated sustained drug release up to 24 h following Higuchi kinetics. Ex-vivo permeation across goat cornea and in-vivo pharmacodynamic studies demonstrated enhanced and prolonged intraocular pressure reduction compared to the marketed suspension. The short-term stability testing indicated that the ocular insert retained the characteristics of %Transmittance, pH, Assay and % drug release. Overall, the results suggest that for better therapeutic efficacy and adherence in glaucoma treatment, the dual-drug loaded ocular insert provides a new, patient-friendly substitute for traditional ophthalmic dosage forms.