Abstract

A method for preparing an easily-swallowed, powder-free, gastric-disintegrable and thinly-coated aspirin tablet, which does not have the characteristic aspirin taste, does not produce the esophageal discomfort of an uncoated aspirin tablet and does not disintegrate in the stomach materially slower than the uncoated aspirin tablet, which comprises aqueous spray-coating hydroxypropyl methylcellulose onto all exterior surfaces of an aspirin tablet, the amount of hydroxypropyl methylcellulose being between 0.5 and 2.0 parts by weight per 100 parts by weight of the aspirin tablet. An aqueous solution of 2% to 15% by weight of hydroxypropyl methylcellulose and about 15% to 25% w/w of a plasticizer based on hydroxypropyl methylcellulose is sprayed onto uncoated aspirin tablets in a slowly rotating baffled pan in a chamber equipped to measure and control both inlet and outlet air flow rates and both inlet and outlet air temperatures, said air flow rates and temperatures being sufficient to insure rapid evaporation of the water and to provide an evenly-applied thin coating of hydroxypropyl methylcellulose onto the uncoated tablets without causing their decomposition and/or physical disintegration. Preferred pan-rotation speeds, inlet and outlet air flow rates and temperatures are given. Other aspects of the invention are said thinly-coated tablets and said coated tablets when produced by said aqueous spray-coating method.