| abstract |
A sustained-release preparation which comprises a drug-containing core and a multilayered coating layer with which the core is covered and in which any two adjacent layers respectively comprise different mixtures of a hydrophobic organic compound and a water-soluble polymer; and a process for producing a sustained-release preparation having a multilayered coating layer in which any two adjacent layers respectively comprise different mixtures of a hydrophobic organic compound and a water-soluble polymer, characterized by spray-coating a core containing a drug with a solution containing a hydrophobic organic compound/water-soluble polymer mixture, subsequently spray-coating the resultant coating layer with a solution containing a hydrophobic organic compound/water-soluble polymer mixture different from that mixture, and repeating the step. |