Abstract
With the present scenario of development of newer drug delivery systems, correspondingly various routes are also being explored for systemic or local drug delivery to the patients. In the same context, nasal drug delivery is serving as a very effective route for the delivery of therapeutically active compounds. In such drug delivery system, drugs having lower absorption rate can be administered with the use of absorption enhancers through thin nasal mucosal layer. Similarly, drug residence time in the nasal cavity can also be increased by using various synthetic and natural polymers. Some mucoadhesive polymers have been reported to serve both of the above functions. The present review deals in depth with, nasal physiology and factors affecting drugs permeability which special reference to biological and pharmaceutical considerations. Structural features and various nasal delivery systems have also been discussed. Furthermore, applications of various natural polymers for the delivery of small organic molecules, antibiotics, proteins, vaccines and DNA through the nasal route have been extensively reviewed.
Keywords: Absorption rate, mucociliary clearance, nasal mucosa, permeability, permeation enhancement, physiology.
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