Sterile Filter Cloth for Lyophilization

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Solution Overview

Problem

Existing filter products for lyophilization processes face challenges in ensuring sterilization and reusability, often requiring significant effort or resulting in single-use systems that generate waste, due to the lack of sterilization capacity at the point of use.

Innovation Solution

A method for producing a particle-free, sterilely packaged filter product involves cutting filter material into a filter cloth under clean room conditions, followed by ultrasonic cleaning, thermal drying, and packaging with a sterile substrate that allows for subsequent sterilization with ethylene oxide, ensuring the filter remains sterile and free from contaminants until use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If filter cloths are sterilized on-site in existing systems, then sterility is achieved, but significant effort and sterilization capacity are required which may not be available

Engineering Contradiction:
ImprovesterilityVSAvoideffort required
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The filter cloth is pre-sterilized and pre-packaged in sterile packaging before delivery to the point of use. This preliminary sterilization action eliminates the need for on-site sterilization capacity and effort, while ensuring the filter cloth arrives already sterile and ready for immediate use in the lyophilization process

Inventive Principle:
Principle #10Preliminary action

2Reliability

If filter cloth and tub are welded together as a single-use system, then sterility is maintained, but large amounts of avoidable waste are generated

Engineering Contradiction:
ImprovesterilityVSAvoidwaste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system is divided into separate components: a reusable tub and a disposable pre-sterilized filter cloth packaged in sterile packaging. This segmentation allows the expensive tub to be reused multiple times while only the filter cloth is discarded, significantly reducing waste compared to welding them together as a single-use system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The filter cloth is designed as a disposable component that is pre-sterilized and packaged. After single use, it is discarded while the expensive tub is reused. This approach maintains sterility through proper packaging and disposal rather than requiring the entire system to be disposable

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If filter material is cut and processed extensively to ensure particle-free quality, then high quality is achieved, but complex processing steps are required

Engineering Contradiction:
Improveparticle-free qualityVSAvoidprocessing steps
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The filter cloth is pre-cut to the required dimensions and pre-cleaned in an ultrasonic bath during manufacturing, then packaged in sterile packaging. This preliminary preparation eliminates the need for complex processing steps at the point of use, requiring only simple unpacking and installation while maintaining high particle-free quality

Inventive Principle:
Principle #10Preliminary action

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

This method produces a high-quality, sterile, and particle-free filter product that can be easily deployed with minimal effort, maintaining sterility and reducing waste by allowing for reusable systems.

Implementation Method 1

The ultrasound excitation creates cavitation bubbles in the cleaning medium, which fill with steam and collapse under the influence of external pressure in the form of a bubble implosion. If this bursting of the steam bubbles occurs in the area of contamination on the filter cloth, it blasts the contamination off the filter cloth

Methodology Applied
Scientific EffectCavitation: Cavitation

Implementation Method 2

the filter cloths stacked in the basket can be placed with the basket in the drying cabinet and treated there under the influence of heat and steam extraction

Methodology Applied
Scientific EffectThermal drying: Evaporation

Data Source

PatentEP3721975B1Method for producing a particle-free sterile packaged filter product
Publication Date: 2022.09.21 KOGEL JURGEN
  • EP3721975B1 patent drawingFigure 1~2

AI summary

It is known to use filter cloths to prevent contamination of chemical products, for example. Such filter cloths are known to be used in connection with tank systems in which freeze-drying of products, such as pharmaceuticals, is carried out. In known processes, the filter cloths must be sterilized immediately before use to prevent contamination of the product in the tank system. The invention provides for storing the filter cloth in a filter product, the manufacture of which includes cleaning in an ultrasonic bath, drying of the cleaned filter cloth, and sealing in sterile packaging, so that the filter cloth can be used on-site without any special sterilization steps.