摘要:
Zeolite NaA can be produced with a very short crystallization time, if an alumino-silicate gel of particular properties is prepared and heated at about 95.degree. C. The gel which is prepared by combining solutions of sodium aluminate and sodium silicate must contain a limited amount of water, be of a single phase and having a high viscosity. Gels of this nature can be heated for a fraction of an hour to yield essentially completely crystallized Zeolite NaA with no crystalline impurities.
摘要:
Methods and arrangements for forming a color gradient on a pharmaceutical dosage forms such as tablets are disclosed. In preferred aspects of the invention, a coating layer is applied to a tablet core so that the coating layer is different from the color of the tablet core. The coating layer is etched by one or more lasers to remove selected portions thereof and reveal the core. Removal of selected portions of the coating layer, while other portions remain unetched by the laser(s), causes a variation in the color of the coating layer. The color of the tablet core may be visible at locations at which portions of the coating layer have been entirely removed while the color of the coating layer, i.e., the color of any of the color coatings thereof, is visible at locations at which portions of the coating layer have been only partially removed or not removed at all.
摘要:
Method for printing on a pharmaceutical tablet by etching a printing plate to form a pattern of etchings therein within an area corresponding to an outline of the tablet, varying the ink-retaining volumes of the etchings in a pre-determined manner and in a direction across the etching pattern from one side to an opposite side, placing ink into the etchings, and transferring ink from the etchings in the etched printing plate onto an outer surface of the tablet. Variations in the ink-retaining volumes of the etchings cause a larger amount of ink to be transferred from etchings having a larger ink-retaining volume than from etchings having a smaller ink-retaining volume during the ink transfer stage. This causes different changes in the color of the outer surface of the tablet dependent on the amount of ink being transferred.