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Torque rheological parameters to predict pellet quality in extrusion-spheronization
J L P Soh1, C V Liew, P W S Heng
1Department of Pharmacy, National University of Singapore, 18 Science Drive 4, S117543, Singapore.
International Journal of Pharmaceutics
|April 1, 2006
Summary
Torque rheometry effectively predicts microcrystalline cellulose (MCC) pellet quality. This method simplifies material evaluation, reducing costly pre-production steps for pharmaceutical formulations.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
- Chemical Engineering
Background:
- Microcrystalline cellulose (MCC) is a key excipient in pharmaceutical formulations, particularly for pellet production via extrusion-spheronization.
- Evaluating MCC quality and predicting pellet performance is crucial for consistent drug product manufacturing.
- Traditional methods for assessing MCC suitability can be time-consuming and resource-intensive.
Purpose of the Study:
- To investigate the feasibility of using torque rheological characterization to predict the quality of MCC pellets.
- To establish correlations between rheological parameters and the physical properties of MCC and its mixtures.
- To demonstrate the utility of torque rheometry for pre-formulation assessment of MCC grades.
Main Methods:
- Eleven MCC grades and their binary mixtures with lactose (3:7 ratio) were analyzed at various water contents.
- A mixer torque rheometer (MTR) was used to determine rheological properties, focusing on maximum torque and cumulative energy of mixing (CEM).
- Correlations were established between torque parameters (CEM((MCC))) and physical properties (crystallinity, pore volumes, densities) and pellet quality.
Main Results:
- Cumulative energy of mixing (CEM) values for MCC powders correlated significantly with their physical properties.
- Strong correlations were observed between torque parameters and pellet properties for both MCC powders and MCC-lactose mixtures.
- This predictive relationship remained valid across a broad range of water content, simplifying rheological assessment.
Conclusions:
- Torque rheometry is a valuable tool for predicting microcrystalline cellulose pellet quality.
- This technique effectively aids in comparing and evaluating different MCC grades, especially for substitutions.
- Utilizing torque rheometry can substantially reduce the need for extensive and costly pre-production optimization.
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