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Unloading and postcompression viscoelastic stress versus strain behavior of pharmaceutical solids
Journal of Pharmaceutical Sciences
|April 1, 1983
Summary
This study measured the viscoelastic properties of direct compression tablets. Tablet composition significantly impacts elastic and viscous behaviors, predicting capping and lamination risks.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
Background:
- Understanding tablet mechanical properties is crucial for direct compression.
- Viscoelasticity influences tablet performance and manufacturing.
Purpose of the Study:
- To characterize the viscoelastic behavior of drug and excipient compacts.
- To correlate viscoelastic properties with tablet compression parameters and failure modes.
Main Methods:
- Utilized a rotary press instrumented for stress and strain measurement.
- Applied three-dimensional viscoelastic theory for data analysis.
- Modeled tablet behavior using elastic-in-dilation and Kelvin-in-distortion components.
Main Results:
- Tablets exhibited elastic behavior in dilation.
- Distortion showed both viscous and elastic contributions, modeled as a Kelvin solid.
- Viscoelastic parameters varied with tablet composition and compression conditions.
Conclusions:
- Tablet composition dictates viscoelastic response during compression.
- Viscoelastic parameters can predict capping and lamination.
- This analysis aids in optimizing direct compression formulations and processes.
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