8 STABILITY OF PECTIN-BASED DRUG DELIVERY SYSTEMS

摘要

1INTRODUCTION The delivery of drugs through the alimentary tract following oral administration via the mouth (the "oral delivery route") remains the most popular method of drug administration for both medical staff and patients alike largely due to convenience, capacity and ease of administration. However, oral drug delivery can be inefficient due to poor absorption, hostile conditions e.g. due to acidic conditions present in the stomach or degradation by digestive enzymes and particularly due to metabolism in the liver (widely known as the "hepatic first pass effect"). A relatively slow onset of action can also be an issue following oral administration even for well absorbed drugs. Recent research has therefore focused on drug absorption through nasal epithelia, although rapid clearance can be an issue for simple nasal formulations. To address these problems there has been significant interest in macromolecular-based carrier and mucoadhesive systems; these approaches are of growing importance. An outstanding example, one particularly successful system of delivery using pectin - a dietary fibre polysaccharide from the cell walls of fruit - is now utilised (PecSys?) in a nasal product recently approved for commercial sale (Fentanyl Nasal Spray marketed as PecFent? / Lazanda by Archimedes Pharma).