Formulation Studies of Furosemide-Amiloride HCI Combination Tablets

Abstract

During the formulation studies of a furosemide-amiloride HCl combination tablet, an unexpected interaction between the two drugs was encountered. The drugs tended to form aggregates when in contact with the dissolution medium during dissolution testing. This phenomenon decreased the dissolution of both actives significantly. Various formulas were tried to eliminate this problem. Granulation of the formulation with povidone produced a tablet with good dissolution properties. A possible mechanism for preventing the formation of furosemide-amiloride HCl aggregates in the presence of povidone is described.