Stability and Dispersion Characteristics of Furosemide Powder for Suspension with Additional Water

Abstract

A furosemide powder for suspension two milligrams/milliliter was reformulated by adding water to disperse powder prior the addition of sticky vehicle. This was conducted to address problems of old formulation (without addition of water) in which the powder could not be mixed with sticky vehicle alone. The reformulated suspension was prepared by combining (a) furosemide powder triturated from three tablets of furosemide 40 mg. put in an amber bottle, (b) vehicle 55 ml (formulation of 100 ml: 1.4%CMC mucilage 17.83 ml, 70%sorbitol 20 ml, syrup USP 50 ml, parabenconc. 1 ml, and purified water 11.17 ml), and (c) five milliliters of water (with 1% paraben). Stability characteristics were analyzed by comparing the reformulated suspension against a standard (90-110%LA,pH 7-10) and stability’s reference of the old formulation. Moreover, physical dispersion was compared between the reformulation and old formulation by 24 pharmacists(blinded method). Results revealed that furosemide amounts of the reformulated suspension were within the standard range (92.4+0.3%LA, pH 5.38), being stable at 25^oC for 60 days, while the old formulation was stable for only 29 days at 25^oC. All pharmacists approved that the reformulated suspension exhibited more powder dispersion. In conclusion, the reformulated furosemide suspension showed better stability and powder dispersion than the old formulation.