Patent ID: 6955821

Claim:
A modified release drug product comprising a first quantity of guaifenesin in an immediate release formulation wherein the guaifenesin becomes bioavailable in a subject's stomach; a second quantity of guaifenesin in a release-delaying matrix; and at least one additional drug, wherein the release-delaying matrix comprises a hydrophilic polymer and a water-insoluble polymer in a weight ratio of hydrophilic polymer to water-insoluble polymer from about 1:1 to about 9:1, wherein the immediate release formulation guaifenesin has a C max in a human subject equivalent to the C max obtained when a dose of a standard immediate release formulation having one third the amount of guaifenesin is dosed, and immediately after administration the serum concentration of guaifenesin peaks in about an hour, followed by a gradual serum concentration decrease over twenty-four hours but the serum concentration of guaifenesin never decreases below the minimum concentration of said standard immediate release formulation over twelve hours, and wherein the drug product releases a therapeutically effective bioavailable guaifenesin dose for at least twelve hours after a single dose in the human subject according to serum analysis.