Alternative routes for drug delivery

The buccal mucosa, which lines the inside of the cheek, has been investigated as an alternative route for drug delivery, especially for proteins and peptides. There are many advantages associated with the use of the buccal mucosa as a site for the delivery of drugs into the systemic circulation. Since blood flow from the buccal epithelium drains directly into the internal jugular... 

Drugs chosen for delivery via a transdermal drug-delivery system must adequately penetrate the skin in such a way that the system determines the delivery rate that should be fairly constant. In addition, the drug must not irritate or sensitize the skin. It is hoped that in the future more drugs will be developed for transdermal delivery. This could become an alternative route for drug delivery to children who have difficulty with oral administration. 

To modulate the rate and extent of therapeutic protein exposure in target tissues, scientists have considered other routes of administration. These alternative routes of drug delivery will be discussed below. All available data suggest that protein bioavailability is expected to be low for nonparenteral routes of administration (i.e., less than 10%). 

Hussain, A. A., Dakkun, A., and Itoh, S. Nasal absorption of ondansetron an alternative route of drug delivery for nausea control. AAPS PharmSci 1(4 Suppl.), 1999. 

As for all other alternative routes, the ocular delivery of proteins is impeded by a permeation barrier and enzymatic metabolism barriers (created by the existence of peptidases in the ocular tissue). In addition, major limitations of this route of delivery are the perceived sensitivity of the eye, the potential hypertonicity of the drug solutions, and the limited volumes that can be applied without spillage from the eye. 

HF as well as sweat glands are ideal targets for drug delivery and may represent an alternative to the intercellular route of skin permeation. HF, in contrast to the stratum corneum, represent an efficient long-term reservoir (up to 10 days) for topically applied substances, as their depletion occurs only through the slow processes of sebum production and hair growth [150-152]. The molecules that... 

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