Patent ID: 6238704
Filing Date: 2001-05-29
Classification: A61K

Abstract:
A process for preparing a sustained-releasing preparation having a sustained-releasing layer formed by miscibilization of a plasticizer, ethylcellulose, and wax, wherein miscibilization is a phenomenon wherein a plasticizer accelerates cohesion and agglutination of ethylcellulose particles and creates a space into which wax penetrates upon heating, which comprises the following steps:(1) preparing a granule containing a medicinally active ingredient;(2) coating said granule with wax in an amount of 20 to 120% by weight to the weight of ethylcellulose;(3) coating said granule with aqueous ethylcellulose latex containing the plasticizer in an amount of 5 to 50% by weight to the weight of the ethylcellulose;(4) coating said granule with a water soluble polymer, in an amount of 1 to 5% by weight to the weight of the granule obtained from steps (1) to (3); and(5) forming the sustained-releasing layer by heating the granule at 50.degree. C. to 90.degree. C.,wherein the sequence of steps (2) and (3) may be inverted, repeated, and/or carried out simultaneously.