Abstract
In the pharmaceutical industry, contoroled-release drug has been paid considerable attension from a view point of Drug Delivery System, DDS. The liquid atomization technique has been applied to the pharmaceutical process, by which the surface of granules or powders fine in size is able to be effectively coated. The contoroled-release drug is usually prepared by the above mentioned coating technique.
On the basis of the above mentioned pharmaceutical situation, the present review paper concerns, two coating processes which prepare the typical contoroled-release drugs, respectively. One of them is a process for preparing sustained-release theophylline; spherical theophylline granules are prepared by use of a coating apparatus of the fluidized tumbled bed type, followed by coating the surface of the granules with ethylcellulose film. The theophylline thus coated exhibits the dissolution rate in the gas-trically simulated juice lower than that of non-treated theophylline. The another is that for promoting the dissolution of Indometacin. A jetcoating system coats the surface of potato starch powder with micro crystalline indometacin which shows the rate of dissolution much higher than that of the non-treated indometacin.
