Bioadhesive Systems as Platform for External and Internal Therapy

Abstract

Diclofenac sodium is a nonsteroidal anti-inflammatory drug • (NSAID) that displays potent analgesic, anti-inflammatory and antipyretic activities. It can be used perorally or topically giving

systemic and local effect respectively. Although diclofenac is completely absorbed from the gastrointestinal tract after oral administration, it is subject to first pass metabolism so that only 50- 60% of the drug reaches the systemic circulation in the unchanged

form. Moreover, peroral administration of diclofenac sodium results in gastrointestinal disturbances ranging from abdominal discomfort, nausea, vomiting to serious gastrointestinal bleeding or peptic ulcers. The adverse effects and the extensive hepatic first-pass effect associated with the peroral administration of diclofenac sodium necessitates the formulation of diclofenac buccal discs that release the drug in the buccal cavity giving local effect then absorbed from the buccal mucus membrane giving systemic effect. The use of the buccal route of administration is limited due to the lack of dosage form retention at the site of absorption. Consequently, bioadhesive polymers were employed in formulation of the buccoadhesive discs.

The work in this thesis is divided into four chapters:

Chapter I: An Improved Design for In-vitro Measurement of Adhesion Properties of Pharmaceutical Bioadhesive Systems. Chapter II: Comparative Study of Mucoadhesion and Release Properties of Different Bioadhesive Polymer Systems. Chapter III: Formulation and Evaluation of Diclofenac Sodium Buccoadhesive Discs. Chapter IV: Bioavailability Assessment of the Selected Diclofenac Sodium Buccoadhesive Disc.