Chitosan as a Delivery System for the Transmucosal Administration of Drugs

Therapeutic materials such as drugs and vaccines can be introduced to the body by many different routes of administration, although conventionally, over many years, parenteral and oral delivery have been the routes of choice [1,2]. The route of preference will be dependent on many factors; these include required speed of onset of action and bioavailability, the dose (potency) and physicochemical properties of the therapeutic substance, patient convenience, and therapeutic indication. Agents used in acute situations are often given by injection directly into the blood stream, into a muscle, or into the subcutaneous tissue [3]. Some drugs can be delivered across the skin using transdermal patches if they have the required physicochemical properties to include a reasonable high lipophilicity and potency. With regard to patient convenience and compliance with dosage regimens, noninvasive, noninjectable products are normally selected.