Compaction Behavior Of Model Formulations Using Smooth Rolls On Different Surfaces

Roller compaction is a very attractive dry granulation technology. However, it is a complex process. Many parameters (feed rates, compaction pressure, roll speed, roll gap and roll surface) are involved and lack of understanding of compaction mechanisms often result in a product that does not possess the desired characteristics. The roller compaction process is often used successfully within the pharmaceutical industry at production scale based on empirical approaches used to define and optimize the process.

These approaches often fail to predict the product quality due to variability that occurs in ribbon quality due to changes either in incoming raw materials or due to process variability. Therefore, physical-chemical properties of the active materials and excipients that are determined in the early formulation development must be fully understood to finalize the process parameters.

Moreover, the particle size distribution of granulation should be well controlled as it influences several aspects of the drug product such as mechanical properties, content uniformity, compression characteristics and dissolution performance. It is well known that roll compaction process often causes materials to lose reworkability or loss of tabletability depending on the processing conditions. Roll surface does play a critical role on the successful compaction of powder materials. Any decision on selecting the best roll surface configuration for roller compaction process should be based on (a) roll capability to produce ribbons with constant thickness, (b) the ability to produce friction to maintain minimized slip region, (c) generating a lower temperature during compaction and (d) offering higher throughput to meet the production demands.