Roll compaction/dry granulation: comparison between roll mill and oscillating granulator in dry granulation

Area of Science:

• Pharmaceutical Technology
• Chemical Engineering
• Materials Science

Background:

• Granulation is crucial for powder processing, impacting drug delivery and manufacturability.
• Oscillating granulators and roll mills are common techniques for dry granulation.
• Optimizing granulation parameters is essential for achieving desired granule properties.

Purpose of the Study:

• To compare granule properties produced by oscillating granulators and roll mills.
• To evaluate the impact of various operational parameters on granule characteristics.
• To determine the suitability of roll mills as an alternative to oscillating granulators in dry granulation.

Main Methods:

• Employed factorial experimental designs to investigate parameter effects.
• Varied oscillating granulator parameters: rotor speed, angle, mesh aperture, rotor type.
• Investigated roll mill parameters: throughput, speed ratio, roll gap, surface texture.

Main Results:

• All tested parameters significantly affected median particle size, size distribution, and fines (P < 0.05), except oscillating granulator rotor type on fines.
• Only roll mill throughput, first-stage gap, and oscillating granulator sieve size significantly impacted flowability (P < 0.05).
• Granule property differences between the two milling types were not practically significant.

Conclusions:

• Roll mills demonstrate significantly higher capacity (approximately sevenfold) than oscillating granulators.
• Roll mills offer improved energy savings per unit of product.
• Roll mills are a viable and efficient alternative to oscillating granulators for roll compaction/dry granulation.