RECENT ADVANCES IN NONINVASIVE SYSTEMIC DELIVERY OF PHARMACEUTICALS AND BIOPHARMACEUTICALS

Many systemically-active pharmaceuticals and biopharmaceuticals are reportedly subjected to extensive pre-systemic elimination when taken orally. To circumvent this dilemma in systemic delivery, extensive research efforts have recently been devoted to explore various nonparenteral (noninvasive) routes of administration for enhancing systemic bioavailability of pharmaceuticals and biopharmaceuticals, which have been reportedly subjected to extensive pre-systemic elimination, via the bypassing of hepatogastrointestinal ''first-pass'' metabolism. Using nicotine, a pharmaceutical, and enkephalin, a biopharmaceutical, the systemic delivery of pharmaceuticals and biopharmaceuticals through the skin and the various absorptive mucosae has been illustrated. The mechanisms and kinetic processes involved for their systemic delivery are explored and various technical issues encountered are discussed in this article.