Ayhan Savaser
Abstract
Introduction Piroxicam (PX) is an oxicam derivative with potent non-steroidal anti-inflammatory activity. It is used in various acute and chronic musculoskeletal and joint disorders such as ankylosing spondylitis, osteoarthritis and rheumatoid arthritis and in acute gout, dysmenorrhea and sometimes for pain associated with inflammation. According to the Biopharmaceutical drug classification system (BCS), PX is a class 2 drug with low solubility and high permeability. Its pharmacokinetic pattern is characterized by slow and gradual absorption via the oral route. This undesired property, may also increase the amount of gastrointestinal (GI) damage, due to long contact of drug with the mucous of GI system. Thus there is a need for an alternative drug delivery system of PX with better gastro intestinal tolerability . Buccal administration of drugs is a valid alternative to the perioral one since drugs directly diffuse into the systemic circulation. In particular, it is advantageous for those drugs that encounter degradation in the gastrointestinal tract or severe hepatic firstpass metabolism and require the administration of large doses to reach effective therapeutic levels in the target site. This drug delivery route is also an alternative for drugs that have severe side effects on GI system such as PX. By contrast, some drawbacks must be taken into account when a dosage form is proposed for buccal administration. Among these is the need for the dosage form to maintain its position for many hours against Buccal motion and salivary flow, the latter also being responsible for dissolving a possible relevant part of the drug, thus reducing the mucosal absorption. Therefore, the first step in the development of a Buccal dosage form is the selection of an appropriate adhesive. A number of bio adhesive polymers have been investigated for buccal purposes, mainly carbopol, cellulose derivatives such as hydroxypropyl methylcellulose (HPMC) and chitosan.