A Polymer-Based Extended Release System for Stable, Long-term Intracochlear Drug Delivery

Area of Science:

• Otolaryngology
• Drug Delivery Systems
• Biomaterials Science

Background:

• Intracochlear drug delivery is crucial for treating inner ear disorders.
• Maintaining therapeutic drug concentrations within the cochlea remains a challenge.
• Fluticasone propionate is a corticosteroid with potential applications in otology.

Purpose of the Study:

• To evaluate a novel polymer-based drug coating for safe intracochlear delivery.
• To assess the long-term maintenance of physiologically active levels of fluticasone propionate.
• To investigate the impact of this delivery system on hearing function.

Main Methods:

• In vitro dissolution studies assessed drug release profiles.
• In vivo studies utilized a guinea pig model with intracochlear implantation of polymer-coated fluticasone propionate particles.
• Perilymph drug concentrations and hearing thresholds were measured at various time points.

Main Results:

• Drug levels remained within the target range for at least 90 days in most animals, with no initial burst release.
• Fluticasone propionate was detected in perilymph up to 180 days post-implantation.
• Implanted ears demonstrated significantly better hearing preservation compared to contralateral ears.

Conclusions:

• The polymer-based extended-release system effectively provides stable, long-term drug delivery for over 90 days.
• This system supports the potential for achieving sustained therapeutic drug levels via a single intracochlear administration.
• The approach shows promise for improving hearing outcomes in cochlear treatments.