Intranasal Drug Delivery

Abstract

The intranasal administration of drugs is a promising alternative to parenteral administration. The nasal route represents an interesting alternative for drugs which have low oral bioavailability because of degradation in GI tract or extensive mucosal or first-pass metabolism. Enzymatic deactivation is a major problem for drugs of polypeptide nature. Thus, the nasal route with low enzymatic activity and highly vascular tissue with good blood flow may be an effective alternative to the injection of these drugs. Small molecules are almost completely absorbed through the nasal membrane. The absorption of larger size molecules may be achieved by increasing the amount of drug delivered, by reducing mucociliary clearance and/or by coadministration of selected non-toxic permeation enhancers. Due to its accessibilty and excellent patient acceptability, as well as being familiar to population at large, the nasal route seems to be especially interesting for the delivery of peptides and those drugs that must demonstrate immediate therapeutic activity.