FORMULATION AND EVALUATION OF FLOATING DRUGS WITH IMPORTANCE OF FLOATING DRUG DELIVERY SYSTEM

Abstract

The development of gastro retentive dosage forms was necessitated by the need to deliver medications at a specific region of the gastrointestinal tract, the so-called absorption window. Attempts to develop gastro retentive drug delivery systems can be broadly categorized into two groups: those that rely on the natural physiology of the gastrointestinal tract and those that are intended to circumvent it. Approaches such as size or floatation, which rely on delayed stomach evacuation, are dependent on the normal physiological fed state duration of 4 to 8 hours. Low density systems that cause buoyancy (Floating drug delivery system), high density which retains the dosage form in the stomach, raft forming systems, concomitant administration of drugs or excipients which slow the motility of the gastro intestinal tract, bioadhesion to gastric mucosa, and swelling to a large size which prevent passage of dosage form through the pyloric sphincter are the primary approaches studied for gastroretentive dosage forms. Floating Drug Delivery Systems (FDDS) have a lower bulk density than gastric fluids; consequently, they float in the stomach for an extended period of time without influencing the rate of gastric emptying. While the system is afloat on the gastric contents, the drug is slowly and nearly completely released from the system at the desired rate. After the drug's discharge, the residual system becomes susceptible to stomach emptying. This causes an increase in gastro retentive time, bioavailability, and improved control of plasma drug concentration fluctuations. Thus, the floating drug delivery system is a safe and effective drug delivery technology