Nasal drug absorption advantage

Although this section deals mainly with the advantages of excised tissues with respect to nasal drug delivery studies, it is important to highlight some important attributes of nasal in situ perfusion model. Although this method does not provide data on systemic absorption, it enables study of the interactions of nasal mucosal enzymes, peptide substrates, and metabolic inhibitors and their implications for nasal drug absorption [13], It also enables the rate of nasal drug absorption to be determined. 

The administration of drugs by alternative routes avoids absorption and metabolic barriers that may be present in the GI tract. The routes can also provide systematic availability when oral administration is contraindicated due to a physiologic condition, or the route may provide for a concentration-time profile that approaches intravenous dosing profiles. The ophthalmic, nasal, pulmonary, buccal, transdermal, and rectal routes provide one or more of these advantages. 

There is no doubt that the nasal route of administration of peptide and protein drugs is one of the most attractive alternatives to injections because of its convenience, which should assure good compliance by patients. The pharmacokinetic profile of peptide and protein drugs after nasal administration shows the occurrence of quick absorption and can be tailored, in some cases, by formulation approaches. This also may have therapeutic advantages. 

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