Formulation, optimization and evaluation of ocular gel containing nebivolol Hcl-loaded ultradeformable spanlastics nanovesicles: In vitro and in vivo studies

The study aims to improve the ocular delivery of Nebivolol HCL (NBV) belonging to the Biopharmaceutics classification system (BCSII) by using spanlastic nanovesicles (SNVs) for ophthalmic delivery and incorporating them into hydroxypropyl methylcellulose gel with ketorolac tromethamine (KET) as an anti-inflammatory to improve glaucoma complications like Conjunctivitis. SNVs were prepared by ethanol injection technique using span (60) as a surfactant and labrasol as an edge activator (EA). The impact of formulation factors on SNVs properties was investigated using a Box-Behnken design. In vitro evaluations showed that the formulations (F1, F4, and F14), containing Span 60 and labrasol as EA (25%, 50%, and 25%), exhibited high EE% with low PS and high ZP and DI. Additionally, 61.72 ± 0.77%, 58.97 ± 1.44%, and 56.20 ± 2.32% of the NBV amount were released from F1, F4, and F14 after 5 h, compared to 93.94 ± 1.21% released from drug suspension. The selected formula (G1), containing F1 in combination with KET and 2% w/w HPMC, exhibited 76.36 ± 0.90% drug release after 12 h. Ex vivo Confocal laser scanning revealed a high penetration of NBV-SNVs gel that ascertained the results of the in-vitro study. In vivo studies showed a significant decrease in glaucoma compared to drug suspension, and histopathological studies showed improvement in glaucomatous eye retinal atrophy. G1 is considered a promising approach to improving ocular permeability, absorption, and anti-inflammatory activity, providing a safer alternative to current regimens.