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Continuous Mixing Technology: Characterization of a Vertical Mixer Using Residence Time Distribution
Kai T Lee1, James A Kimber1, Giuseppe Cogoni2
1Worldwide Research and Development, Pfizer Inc, Sandwich Kent, UK.
Journal of Pharmaceutical Sciences
|February 19, 2021
Summary
Continuous powder mixing technology (CMT) offers robust and flexible blending for solid oral dosage forms. Its performance is consistent across various material properties and process parameters, ensuring reliable drug product quality.
Area of Science:
- Pharmaceutical Technology
- Chemical Engineering
- Process Analytical Technology
Background:
- Continuous powder mixing technology (CMT) is crucial for solid oral dosage form manufacturing.
- Mixing performance directly impacts critical quality attributes of the final drug product.
Purpose of the Study:
- To investigate the influence of blend material properties and process parameters on CMT performance.
- To characterize the mixing behavior using Residence Time Distribution (RTD).
Main Methods:
- Utilized Residence Time Distribution (RTD) analysis to characterize mixing.
- Employed a near-infrared (NIR) probe to monitor tracer concentration at the mixer outlet.
- Varied process parameters: throughput (15-30 kg/h), impeller speed (400-600 rpm), and hold-up mass (500-850 g).
Main Results:
- CMT mixing dynamics can be modeled using two ideal Continuous Stirred Tank Reactors (CSTRs).
- Mixing predominantly occurs in the lower chamber of the CMT.
- Normalized RTDs remained consistent across tested conditions, indicating robustness.
Conclusions:
- Material properties (API particle size, bulk density) had minimal impact on mixing performance.
- CMT demonstrates robustness and flexibility, allowing independent control of key parameters for continuous blending.
- CMT is a reliable technology for achieving consistent mixing in solid oral dose manufacturing.
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