Patent ID: 8617596

Claim:
A process for producing sustained-release tablets comprising: dry granulating a mixture composed of a hydroxyalkyl cellulose (A) having a viscosity of 1 to 50 mPa*s in a 2% by mass aqueous solution at 20Â° C., a hydroxyalkyl cellulose (B) having a viscosity of 100 mPa*s or more in a 2% by mass aqueous solution at 20Â° C., an active ingredient and an additive, and forming the resulting granules into tablets, wherein a fine powder in which the proportion of fine particles having a particle diameter of 150 Î¼m or less is 99% by mass or more is used for both the hydroxyalkyl cellulose (A) and the hydroxyalkyl cellulose (B), wherein the hydroxyalkyl cellulose (A) is used at 20 to 60% by mass based on the entire mixture, the hydroxyalkyl cellulose (B) is used at 10 to 40% by mass based on the entire mixture, the active ingredient is used at 1 to 30% by mass based on the entire mixture, and the additive is used at 10 to 60% by mass based on the entire mixture, and wherein the total content of the hydroxyalkyl cellulose (A) and the hydroxyalkyl cellulose (B) is 40 to 70% by mass based on the entire mixture.