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US 4,789,549 AGranted
Sustained release dosage forms
AssigneeWarner-Lambert Company
InventorsSadath U. Khan, Pijush K. Chakraborty, Albert T. Grabowski, Reginald Phillips
Life of this patent
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Abstract
A unique sustained release dosage form which prevents the tendency of an initial surge of medicament in the first hour of administration. The control is by a porous membrane coating. The amount of initial release can be varied by varying the proportions of the components of the coatings.
Claims7
A sustained release dosage form comprising an effective amount of a water-soluble therapeutically active medicament in a water soluble polymer matrix which matrix is coated with a semipermeable membrane said coating consisting of effective amounts of
- (a) hydroxypropyl cellulose polymer and
- (b) cellulose acetate phthalate with polyoxpropylene polyoxyethylene block copolymer and acetylated monoglycerides,
- and said coating being water soluble at pHs between about 5.5 and about 6.5.
Dependencies are inferred from the claim text.