Formulation, development, and evaluation of chitosan mucoadhesive microspheres of Atenolol, a selective beta blocker

Abstract

Atenolol, a selective β₁-adrenergic blocker, requires chronic administration for hypertension and related cardiovascular disorders. Conventional oral dosage forms may lead to plasma peak–trough fluctuations and frequent dosing. The present work aimed to develop chitosan-based mucoadhesive microspheres of atenolol to achieve prolonged gastrointestinal residence and sustained drug release. Microspheres were prepared using ionotropic gelation with sodium tripolyphosphate (TPP) as a cross-linking agent. Formulations (F1–F6) were optimized by varying polymer and cross-linker levels. Prepared microspheres were evaluated for percentage yield, particle size, drug loading, entrapment efficiency, flow properties, swelling index, mucoadhesive strength, in-vitro wash-off, surface morphology (SEM), in-vitro drug release, and release kinetics. Microspheres were discrete and spherical, showing acceptable flow and significant mucoadhesion. The optimized formulation (F2) exhibited high yield, satisfactory entrapment, strong mucoadhesion, and sustained release up to 12 h. Release kinetics indicated diffusion-dominant release with swelling contribution, consistent with Higuchi and Korsmeyer–Peppas behavior. The study concludes that chitosan mucoadhesive microspheres represent a promising controlled oral delivery platform for atenolol.