Oral Gastroretentive Floating In-Situ Gelling System of Furosemide

Floating in-situ gel is one of the gastroretentive drug delivery systems represents a revolution in the oral controlled release dosage forms in comparative with conventional oral liquids. They prolong the residence time of the drug that has a narrow absorption window in the absorptive sites like stomach or upper gastrointestinal (GI) tract; since they have a bulk density lower than gastric fluids. Thus they remain buoyant in the stomach without affecting the gastric emptying rate until all the drug release continuously at a slow rate. Furosemide is a high ceiling loop diuretic widely used for patients with congestive heart failure (CHF) to get rid of excess body water, reducing blood pressure, and mobilizing edemas. This study involved formulation of furosemide oral solution which undergoes gelation upon direct contact with gastric fluid and floated using either primary polymers as sodium alginate and gellan gum or in combination with secondary polymers as iota carrageenan and HPMC. Different evaluations were performed on all 35 in-situ gel formulas to measure the gel strength, gelation time, swelling index, content uniformity, floating lag time, floating duration, pH and density.