Preparation and Characterization of Mucoadhesive Loratadine Nanoliposomes for Intranasal Administration

The present study aimed to formulate and characterize mucoadhesive liposomes for intranasal delivery of loratadine. In particular, the formulation was aimed to improve the drug bioavailability and efficacy.

Liposomes were prepared by thin-film hydration method, with soybean phosphatidylcholine and cholesterol as main components. Liposomes were coated with chitosan solution at a concentration of 0.05% and 0.1%, w/v. The formulations were assessed for particle size, polydispersity index (PDI), encapsulation efficiency (EE), thermodynamic behavior, in vitro drug release, mucoadhesiveness, and stability.

Particle size analysis showed that the vesicles of uncoated and coated liposomes with 0.05% and 0.1% chitosan were characterized by size of 193±3.3 nm, 345±4.6, and 438±7.3 nm, respectively. Size distribution for developed formulations was in the acceptable range (PDI <0.7). EE was recorded to be approximately 80%. Chitosan-coated liposomes demonstrated slower release rate as compared to uncoated liposomes. Drug release kinetics profile for all the formulations followed a zero-order model. Chitosan coating improved mucoadhesiveness by more than 3-fold as compared to uncoated liposomes. However, no significant differences were recorded between mucin adsorption behavior of 0.05% and 0.1% chitosan-coated liposomes (p>0.05). For stability studies, liposomes were stored at 4°C for 3 months, and changes in particle diameter, PDI, and EE % were recorded. No significant alternations were reported in particles size, PDI, and drug leakage of coated liposomes.

Liposomes coated with 0.05% chitosan were chosen as the optimum formulation, which demonstrated a significant potential for overcoming the nasal drug delivery limits for short residence time and mucociliary clearance.