Browsing by Subject "feed screw speed"

The roller compaction is a dry granulation method which is commonly used in the pharmaceutical industry. The purpose of the roller compaction is to increase the particle size, narrow the particle size distribution and improve the powder flowability. In the roller compaction process, powder is fed between two press rolls. The relevant process parameters of the roller compaction (roll pressure, roll speed and feed screw speed) affect the formed briquette or ribbon density. The briquette is broken down and sieved by using a crusher. General problems of the roller compaction are incompressible fine powder and the low yield. AGS (Aerodynamic Granulating System) is a patented supplement for the roller compaction. Its operation is based on the air flow which sucks the fine particles out of the granule mix. The granules and the fine particles are collected into their own containers. When the system is fully optimized the fine particles can be recycled between the press rolls (a closed loop). In this case, it is possible to get close to 100 % batch yields. The experimental design of this study was a modified central composite design with three variables and two value levels which was used to find the optimal combinations of the process parameters. The purpose of this study was to compare the gas assisted and the conventional roller compaction methods. The physical properties of granules and tablets made of these granules were compared. The strengths and weaknesses in AGS process were also studied and development ideas for the future were planned. Microcrystalline cellulose was used in this study as a model excipient. The study showed that the granules made by the AGS require higher compression forces in tableting process than conventional granules. The reason for this could be the lower number of contact points between the particles, since the fine particles were removed from the granule mix. The low compression pressure, fairly fast roll speed and small sieve size created good quality granules. The flowability and compression properties of these granules were good as well as particle size distribution. In this study, any major differences were not observed between these two granulation methods.