Roller compaction is a dry granulation process used to make coarse granules prior to final compression. Typical excipients used in roller compaction are Lactose, Microcrystalline Cellulose, and Magnesium Stearate as the lubricant. These and other ingredients of various particle sizes, are fed through a funnel into two knurled rolls which compact the powder into ribbons. The ribbons are then lightly milled to a uniform, non-dusting, free flowing particle size suitable for tabletting. This technique is often used with poor flowing API’s, or when content uniformity is an issue.
However, the speed of which the blended excipients can pass through the rollers, is often a rate limiting step in roller compaction. Magnesium Stearate is often used in the blend to lubricate the excipients on the rolls, but this can have detrimental effects on the final compaction of the granules, if the addition is not done with careful precision & timing. Kerry scientists have found a way to increase roll throughput by providing adequate lubrication in the pre-granules, without the need for any external lubricant. Excellent content uniformity is also maintained.