Nasal mucosa surface area

The use of a bioadhesive, polymeric dosage form for sustained dehvery raises questions about swallowing or aspirating the device. The surface area is small, and patient comfort should be addressed by designing a small (less than 2 cm ), thin (less than 0.1 mm (4 mil) thick) device that conforms to the mucosal surface. The buccal route may prove useful for peptide or protein dehvery because of the absence of protease activity in the sahva. However, the epithelium is relatively tight, based on its electrophysiological properties. An average conductance in the dog is 1 mS/cm (57) as compared to conductances of about 27 and 10 mS/cm in the small intestine and nasal mucosa, respectively (58,59) these may be classified as leaky epitheha. 

The surface area available for absorption in the buccal mucosa is much smaller than the gastrointestinal, nasal, rectal, and vaginal mucosae. The buccal mucosa is continuously bathed by saliva, and the secreted saliva lowers the drug concentration at the absorbing membrane. These two factors, along with the permeability... 

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