Bioadhesive polymers in peptide drug delivery

A frequently encountered problem with the peptide-based drugs which are becoming available is that these agents must generally be administered by injection. There is therefore considerable research interest in alternative delivery routes, such as the buccal and nasal mucosae, and the conjunctiva. This paper reports some quantitative considerations of peptide delivery via the buccal, nasal, ocular and gastrointestinal routes, based on estimates of permeability coefficients and other necessary parameters. Rates of delivery and the resulting systemic levels are calculated for some peptide drugs, and compared to therapeutic levels: situations are identified in which bioadhesive formulations may be of benefit.