Novel hybrid tri-polymer hyalurosomes: unlocking next-generation trans-tympanic therapeutics through multi-Scale evaluations

Acute otitis media (AOM) remains one of the most common middle ear infections, particularly in children, necessitating advanced non-invasive therapeutic strategies. This study introduces Novel Hybrid Tri-Polymer Hyalurosomes, an innovative vesicular system designed to enhance trans-tympanic delivery of ciprofloxacin (CFX). The nanosystems were fabricated using the ethanol injection technique and optimized via a 2³ factorial design, evaluating the effects of hyaluronic acid (HA): drug ratio (Factor-A), surfactant: HA ratio (Factor-B), and L121: Brij L4 ratio (Factor-C) on critical quality attributes. The optimized formula, selected using a high desirability index (0.996), exhibited high entrapment efficiency (EE%) of 90.28 %, small particle size (PS) of 218.15 nm, and promising zeta potential (ZP) of -40.4 mV. Transmission electron microscopy (TEM) confirmed the uniform spherical morphology of the optimized formula, which also exhibited a characteristic bi-phasic sustained release profile and pseudoplastic rheological behavior, enhancing ease of application and retention at the administration site. Moreover, the formulation demonstrated excellent storage stability and markedly improved mucoadhesive properties. Ex vivo permeation studies revealed a 2.53-fold enhancement ratio compared to CFX solution. Microbiological assessments showed significantly lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i>, along with superior biofilm inhibition activity. Confocal laser scanning microscopy (CLSM) confirmed deeper tissue penetration, consistent with the permeation findings. Additionally, in vivo histopathological evaluation demonstrated the safety of the optimized formula with no observable tissue irritation or damage. Collectively, Novel Hybrid Tri-Polymer Hyalurosomes present a promising non-invasive trans-tympanic delivery platform, holding significant potential for advancing AOM therapy.