| abstract |
Instead of using a uniform aqueous solution of a water-soluble cellulose ether as a coating liquid of solid medicament forms, e.g., granules and tablets, to form a film-forming layer, an aqueous dispersion of a cellulose ether, which is soluble in cold water but insoluble in hot water, is used as a coating liquid at a temperature higher than the solubilization temperature, i.e. the critical point of the solubility behavior, followed by plasticization of the cellulose ether particles with water to cause fusion thereof. The coating liquid is freed from the limitation by the flowability even when the content of the cellulose ether is much higher than in the conventional solution-type coating liquid. In addition to the greatly decreased time taken for forming a coating layer in a desired coating amount, moreover, cellulose ethers having a high degree of polymerization, which cannot be used in the conventional method, can be used so that the resultant film-coating layer is much stronger than otherwise to provide a sustainedly releasing coating layer. |