Controlled release formulation
First Claim
1. A controlled release pharmaceutical formulation from which a pharmaceutical of a basic character is released at a controlled rate irrespective of the pH of the environment, consisting essentially of a pharmaceutical of a basic character, a pH-dependent polymer which is a salt of alginic acid, in an amount of from about 15 to about 45% by weight of the formulation, said salt of alginic acid having a viscosity of within the range of from about 4 to about 500 centipoises in 1% solution at 25°
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a pH-independent hydrocolloid gelling agent having a viscosity within the range of from about 50 to about 100,000 centipoises in 2% solution at 20°
C., in an amount within the range of from about 3 to about 35% by weight of the formulation, and binder, said formulation being free of calcium ion.
1 Assignment
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Accused Products
Abstract
A controlled release pharmaceutical formulation is provided which releases a pharmaceutical of a basic character at a controlled rate regardless of the pH of the environment, which formulation includes a basic pharmaceutical, up to about 45% by weight of a pH dependent polymer which is a salt of alginic acid, such as sodium alginate, up to about 35% by weight of a pH-independent hydrocarbon gelling agent having a viscosity of up to about 100,000 centipoises in 2% solution at 20° C., binder and excipients.
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Citations
20 Claims
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1. A controlled release pharmaceutical formulation from which a pharmaceutical of a basic character is released at a controlled rate irrespective of the pH of the environment, consisting essentially of a pharmaceutical of a basic character, a pH-dependent polymer which is a salt of alginic acid, in an amount of from about 15 to about 45% by weight of the formulation, said salt of alginic acid having a viscosity of within the range of from about 4 to about 500 centipoises in 1% solution at 25°
- C.;
a pH-independent hydrocolloid gelling agent having a viscosity within the range of from about 50 to about 100,000 centipoises in 2% solution at 20°
C., in an amount within the range of from about 3 to about 35% by weight of the formulation, and binder, said formulation being free of calcium ion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification