Absorption nasal drug delivery

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. 

S. S. Davis and L. Ilium. Absorption enhancers for nasal drug delivery. Clin Pharmacokinet 42 1107-1128 (2003). 

Administration of drug to the therapeutic target site or absorption site in the nasal cavity is the first step in nasal drug delivery. Uniform distribution over the affected area is desirable for the treatment of nasal symptoms, whereas targeting of the favorable absorption sites... 

Merkus, F.W.H.M., et al. 1993. Absorption enhancers in nasal drug delivery—Efficacy and safety. J Control Release 24 201. 

For nasal drug delivery, it has been suggested that two mechanisms of absorption exist, based on the physicochemical properties of the drug ... 

Microspheres can be used as nasal drug delivery systems for systemic absorption of peptides and proteins. 

Peptide and protein nasal drug delivery have challenges related to their unique physical and chemical properties and comprise issues of chemical stability, loss due to physical absorption (especially for low-dose/high-potency molecules) and self-aggregation. The two key factors for nasal delivery of peptides are molecular mass and lipophilicity. The transitional area between a predicted good absorption and a predicted increasing difficulty of absorption is a molecular mass of about 1,000 (McMartin et al. 1987). Complete absorption of a peptide, by... 

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