Abstract: 
To formulate and evaluate the Levosalbutamol sulphate loaded microspheres of Chitosan and microspheres of Flax seed Mucilage in which both the polymers were checked as potential mucoadhesive agents and crosslinking was done with Glutaraldehyde for prolonging drug release for asthma therapy. Chitosan and Flax seed mucilage (by drying in Hot Air Oven) were used in appropriate concentration and crosslinked microspheres were prepared by Spray drying. They were evaluated for % Entrapment efficiency, Swelling behavior, % Mucoadhesion and In vitro drug release. The optimized batches were subjected to Particle-size distribution, Scanning-electron microscopy, Aerosolization behavior and Stability study. Microspheres having Chitosan polymer:Drug ratio of 2:1 and 0.6% of Glutaraldehyde and that of Flax seed Mucilage:Drug ratio of 3:1 and 0.9% of Glutaraldehyde had good mucoadhesion ability (89.50% and 85.11% respecively). Release rate was retarded up to 8 h and follows non-fickian diffusion. Particle-size distribution of optimized batches was represented by span index (3.822 and 2.953 respectively) and value was nearer to marketed product (1.975). Aerosolization behavior could be comparable with marketed product. Stability study showed no changes. The overall results of this study indicate that microspheres described above may be considered as Dry Powder Inhaler of Levosalbutamol sulphate for asthma.

Keywords: Mucoadhesive Microspheres, Levosalbutamol Sulphate, Chitosan, Flax Seed Mucilage, Spray Drying, Dry Powder Inhaler.