ABSTRACT
The gold standard for bringing a product to market is perhaps still an oral dosage form such as a tablet or a capsule. However, in many cases, this is not possible due to a variety of reasons (e.g., in the case of a large protein, the enzymatic and absorption barriers of the gastrointestinal (GI) tract will not allow any signi•cant blood levels to be achieved following oral administration. In such cases, a company will often bring the product to market in an injectable dosage form. These parenteral dosage forms have their own disadvantages related to costs associated with administering the injection in a supervised clinical setting as well as compliance issues related to fear of needles as well as the need for multiple injections over short periods of time. Companies are therefore always exploring noninvasive alternate routes of administration. Transdermal delivery is one such promising alternative, especially because the patch is now a household word. The credit for the latter goes to over 15 different drugs that have been successfully commercialized, including the well-known nicotine patches. Sometimes, a company may also look at transdermal and other delivery routes for marketing advantages when a patent is about to expire and generic competition is forthcoming.
