Abstract: 
In this study, a novel mucoadhesive microsphere for nasal administration was developed and investigated. The carvedilol loaded PLGA microspheres were prepared by a spray-drying technique that can be proposed as an alternative to the conventional methods for preparation of microspheres. The microspheres were evaluated with respect to the production yield, particle size, incorporation efficiency, swelling property, in vitro mucoadhesion, in vitro drug diffusion, ex-vivo permeation study, histopathological examination and stability study. Microspheres were characterized by differential scanning calorimetry, scanning electron microscopy and X-ray diffraction study to gain insights into the nature of interaction between the drug and polymer. It was found that the particle size, swelling ability and incorporation efficiency of microspheres increases with increasing drug to polymer ratio. Microspheres show adequate mucoadhesion and do not have any destructive effect on nasal mucosa. The results of morphological examination indicated that the PLGA 50:50 microspheres possessed a smooth and spherical appearance with average particle size of 10-25 µm. Release profiles of carvedilol from the microspheres displayed an anomalous transport mechanism. The investigations of these microspheres as vehicle for nasal delivery showed that PLGA microspheres may be considered as a promising nasal delivery system.

Keywords: Carvidilol, Nasal, PLGA, Microspheres, Spray Drying.