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Intrinsic dissolution rate modeling for the pharmacopoeia apparatus rotating disk compared to flow channel method
Amelie M Mattusch1, Gerhard Schaldach1, Jens Bartsch1
1Department of Biochemical and Chemical Engineering, TU Dortmund University, Germany.
Pharmaceutical Development and Technology
|March 19, 2024
Summary
Dissolution testing errors in the rotating disc apparatus are caused by inhomogeneous flow. Using a flow channel or correcting rotating disc data improves intrinsic dissolution rate accuracy for drug development.
Area of Science:
- Pharmaceutical Sciences
- Chemical Engineering
- Physical Chemistry
Background:
- Accurate in vitro dissolution rate measurement is crucial for understanding drug characteristics.
- Hydrodynamics are considered a primary factor influencing drug dissolution.
- The rotating disc apparatus is a common method for dissolution testing.
Purpose of the Study:
- To investigate the impact of mixing behavior in the rotating disc apparatus on intrinsic dissolution rate measurements.
- To identify and quantify systematic errors in dissolution rate calculations due to inhomogeneous flow fields.
- To propose alternative methods or corrections for more accurate dissolution testing.
Main Methods:
- Conducting experiments using the rotating disc apparatus and a flow channel.
- Performing computational fluid dynamic (CFD) simulations to analyze flow fields.
- Analyzing the influence of experimental time and fluid velocity on dissolution rates.
- Developing a correction method for rotating disc data.
Main Results:
- The rotating disc apparatus generates an inhomogeneous flow field, leading to systematic errors in intrinsic dissolution rate calculations.
- Both experimental time and fluid velocity significantly affect the observed error.
- A flow channel with uniform overflow minimizes these errors.
- A method for comparing and adjusting rotating disc data with flow channel data using Reynolds number and a correction factor was proposed.
Conclusions:
- The standard rotating disc apparatus can introduce significant errors in intrinsic dissolution rate measurements due to its hydrodynamics.
- A flow channel apparatus is recommended for more reliable dissolution behavior investigations.
- Adjusted rotating disc measurements can be comparable to flow channel results.
- Modeling apparatus-independent intrinsic dissolution rates at various temperatures is feasible with adapted equations.
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