Controlled release pharmaceutical preparation and method for producing the same
First Claim
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1. A controlled release pharmaceutical preparation comprising:
- (A) a core containing a pharmaceutically active ingredient and succinic acid; and
(B) a porous cellulose film formed on the surface of said core by spraying a water-organic solvent mixture containing ethyl cellulose or a mixture of ethyl cellulose and hydroxypropyl cellulose, said porous cellulose film having a porosity of about 0.4 to 0.9 calculated according to the formula;
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Abstract
Disclosed is a controlled release pharmaceutical preparation, comprising a core containing a pharmaceutically active ingredient, and a porous film of a hydrophobic polymeric substance or a hydrophobic polymeric substance and a hydrophilic polymeric substance, the core being coated with the porous film. Disclosed is also a method for producing the same. The controlled release pharmaceutical preparation of this invention posseses a desired dissolution rate by controlling the porosity of the porous film.
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Citations
6 Claims
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1. A controlled release pharmaceutical preparation comprising:
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(A) a core containing a pharmaceutically active ingredient and succinic acid; and (B) a porous cellulose film formed on the surface of said core by spraying a water-organic solvent mixture containing ethyl cellulose or a mixture of ethyl cellulose and hydroxypropyl cellulose, said porous cellulose film having a porosity of about 0.4 to 0.9 calculated according to the formula;
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6. A method of producing a controlled release pharmaceutical preparation which comprises spray-coating a water-organic solvent mixture containing ethyl cellulose or a mixture of ethyl cellulose and hydroxypropyl cellulose onto the surface of a core containing a pharmaceutically active ingredient and succinic acid to produce a porous cellulose film on said core, said porous cellulose film having a porosity of about 0.4 to 0.9 calculated according to the formula:
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Specification