The present invention is directed to a coating composition for coating a solid
dosage form of a medicament, where the coating composition controls the release
of the medicament, said coating composition comprising (a) at least 50% (w/w) by
dry weight of a water insoluble polymer insoluble in both acidic, basic and neutral
pH, present in the form of an aqueous latex dispersion, (b) a water soluble non-polymeric
component present in a weight ratio of about 5 to about 50% (w/w) by dry weight
of the coating, having a molecular weight of less than about 15,000 daltons and
water solubility in excess of 5 grams per 100 grams of water at room temperature
at 1 atm pressure, said water soluble non-polymeric component being organic and
either solid or liquid; said ratio of water insoluble polymer to water soluble
non-polymeric component ranging from about 95:5 to about 1:1, the solid content
in the coating composition ranges from about 5% to about 25%, said water soluble
component being completely dissolved in the aqueous latex dispersion. The present
invention is also directed to a system for the controlled release of an active
medicament comprising a substrate and a coating, said substrate comprising a therapeutically
effective amount of a medicament in association with a pharmaceutical carrier in
solid unit dosage form, said substrate being uniformly coated with the aforesaid
coating composition.