ABSTRACT
Transmucosal drug delivery refers to delivery of drugs across mucosal tissues such as those of the lung (pulmonary drug delivery), nose (nasal drug delivery), and mouth (sublingual and buccal drug delivery). Rectal and vaginal are less important forms of drug delivery that t into this category. These mucosal tissues tend to be much more permeable than skin, since they are not keratinized. Other advantages of these routes are that they avoid the “rst-pass” effect of hepatic extraction encountered with oral drug delivery and that they are generally less invasive than injectable forms of administration. Disadvantages are mucosal tissues are more sensitive to irritation than either oral or transdermal drug delivery and are less convenient for adhesive systems than transdermal delivery. The tissues of the eye are not mucosal but have some similarities to the latter; thus, ocular drug delivery, normally used for local rather than systemic administration of drugs, is also discussed in this chapter.
