PREPARATION OF DRUG HAVING ENTERIC COATING

PURPOSE:To prepare the titled drug without using an organic solvent, by using a solution obtained by dissolving an enteric cellulose derivative in an alkaline aqueous solution, and adding a carboxylic acid to the solution. CONSTITUTION:An enteric cellulose derivative such as hydroxypropyl methyl cellulose phthalate, carboxymethyl ethyl cellulose, etc. is dissolved in an alkaline aqueous solution (the alkali is e.g. alkali metal hydroxide or carbonate, or ammonia), a carboxylic acid is added to the solution in an amount of >=50%, preferably >=60% equivalent of the alkali, and the resultant solution is applied to a solid drug such as tablet, capsule, etc. by conventional method. To prevent the precipitation of large gelatinous lumps, the carboxylic acid is diluted with water (usually to a concentration of