Granulation steps as wet granulation are applied before the final step of tableting in order to achieve content uniformity, flowability and compressibility. Wet granulation applies water and therefore needs a drying step. To omit this for reasons of cost and API stability dry granulation or roller compaction is a compromise to achieve the desired content uniformity without having water involved and a subsequent drying step.

Studies available in literature mostly focus on the use of MCC and lactose in this application. However, mannitol – nowadays becoming very popular in pharmaceutical formulation due to its high compatibility with almost all APIs – is rarely being covered.

This white paper summarizes several studies which explored tableting behavior and comparative compressibility of various pre-processed and unprocessed mannitol grades in dry granulation processes. As a commonly used approach in dry granulation on an industrial scale, the examples focus on roller compaction (also referred to as roll compaction). The roller compaction behavior of different mannitol grades was investigated in placebo formulations or in combination with enalapril maleate as a model low-dose API. Results of these studies reveal differences in performance and can help guide selection of the best mannitol grade for dry granulation processes.