Nasal drug absorption

Table 5.1 Some factors that affect nasal drug absorption in vivo [2],...

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. 

Correlation Between Nasal Drug Absorption Models... 

During the last decade several in vitro models using excised mucosal segments and monolayers of epithelial cells have been established, providing an opportunity to predict nasal drug absorption in vivo while avoiding problems associated with more complex whole animals [8],... 

In Vitro Cellular Models for Nasal Drug Absorption Studies... 

Experimental Models of Physiological Barriers to Nasal Drug Absorption.366... 

EXPERIMENTAL MODELS OF PHYSIOLOGICAL BARRIERS TO NASAL DRUG ABSORPTION... 

Fig. 4 Variable factors influencing nasal drug absorption, and related key points for practical application.

Diseases affecting nasal mucous membrane. Effect of the common cold on nasal drug absorption is also an important consideration. 

Nasal drug absorption can be accomplished by use of prodrugs, chemical modification of the parent molecule, and use of physical methods of increasing permeability. Special excipient used in the nasal preparations comes into contact with the nasal mucosa and may exert some effect to facihtate the drug transport. The mucosal pores are easier to open than those in the epidermis. The following characteristics should be considered in choosing an absorption enhancer ... 

---