Tablet Capacitance Tomography for Inline Solid Fraction Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining the solid fraction and thickness of pharmaceutical tablets are either qualitative or require multiple devices, lacking robustness and efficiency in continuous manufacturing processes.
Innovation Solution
A device using multiple capacitance sensors with parallel conducting elements to measure relative permittivity and thickness of tablets, allowing for non-destructive, inline determination of solid fraction and hardness, utilizing electrical tomography.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple capacitance sensors are used to measure both thickness and solid fraction simultaneously, then measurement comprehensiveness and batch representativeness are improved, but device complexity increases
Solution Approach 1:
The patent combines multiple capacitance sensors (first and second sensors with different orientations) into a single integrated device that simultaneously measures both thickness and solid fraction. This merging approach allows comprehensive measurement capabilities while consolidating the device structure, resolving the contradiction between measurement comprehensiveness and device complexity.
Solution Approach 2:
The capacitance measurement device is designed to perform multiple functions: measuring thickness, solid fraction, and potentially other tablet properties simultaneously. By making the device universal and multi-functional, the patent achieves comprehensive measurement capabilities without proportionally increasing device complexity, as all measurements are obtained through a single integrated system.
2Productivity
If capacitance sensors are used for non-destructive measurement, then sample integrity is preserved and measurement speed is improved, but the ability to directly determine solid fraction is limited due to capacitance responding to both volume and mass
Solution Approach 1:
The patent introduces orientation as an additional dimension by using capacitance sensors in different orientations (first and second sensors with perpendicular arrangements). This dimensional approach allows the system to disentangle the effects of volume and mass on capacitance measurements, enabling accurate solid fraction determination while maintaining the speed and non-destructive nature of capacitance sensing.
Solution Approach 2:
The patent uses the relationship between capacitance, thickness, and solid fraction as an intermediary model. By establishing mathematical relationships and calibration curves that connect capacitance measurements to solid fraction through the intermediate parameter of thickness, the system can indirectly but accurately determine solid fraction while maintaining the advantages of fast, non-destructive capacitance sensing.
3Reliability
If periodic control using multi-testers is performed, then quality attributes are monitored, but only a small part of the batch (around 0.01%) can be determined due to equipment speed and destructive testing
Solution Approach 1:
The patent implements continuous, real-time measurement of tablet properties throughout the manufacturing process. The capacitance sensors continuously monitor thickness and solid fraction of tablets as they pass through the system, providing ongoing quality control data for the entire batch rather than periodic sampling. This continuous measurement approach dramatically improves batch representativeness while maintaining reliable quality monitoring.
Solution Approach 2:
The patent replaces the mechanical, destructive multi-tester system with an electrical field-based capacitance measurement system. This substitution eliminates the need for destructive physical contact and manual handling, enabling continuous, non-destructive measurement at high speeds that matches production rates, thereby improving both productivity and batch representativeness while maintaining quality control reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables fast, non-destructive, and quantitative measurement of tablet properties, enhancing batch representativeness and supporting Real Time Release applications in pharmaceutical manufacturing.
Implementation Method 1
A device using multiple capacitance sensors with parallel conducting elements to measure relative permittivity and thickness of tablets
Implementation Method 2
utilizing electrical tomography
Data Source
AI summary
The present invention relates to a device for obtaining capacitance measurements for use in determining the relative permittivity and thickness of a pharmaceutical tablet. The invention further relates to a method of determining the relative permittivity and thickness of a pharmaceutical tablet using one or more capacitance sensors. The device and method may be part of a pharmaceutical tableting unit or a pharmaceutical tableting method.