Considerations for Medical Device Manufacturing

HKIE CPD Seminar on “Considerations for Medical Device Manufacturing – Optimization of materials, applications and sterilization and 2008 Healthcare Innovative Solutions by Advanced Medical Plastics” was held on 4 July 2008 in Hong Kong Productivity Council. The followings are summary of the seminar contents.

The first speaker is Mr. Kent Leung who is professional service specialist in 3M. He introduced the basic knowledge for medical device manufacturing such as sterilization, validation, commissioning and performance qualification, etc.

There are 7 principle of sterilization:
1. A process that kills all living forms including spores.
2. The process must have high penetration to reach the product.
3. The process must not destroy the product (non-destructive).
4. The process must be safe.
5. The process shall be easily monitored.
6. The process must be repeatable and controllable.
7. The process must keep the sterile state of the product afterwards (e.g. packaging).

Validation: Demonstrates and documents that a process does what it is supposed to do.


There are 3 common methods for microbiological qualification.
Method A: Survivor curve construction
Method B: Fraction negative method
Method C: Half-cycle method

All methods employed have the following assumptions:
- Organism population is homogeneous
- Process parameters, with the exception of time are constant from run to run
- A semi-logarithmic survivor curve exists
- Exposed & unexposed organisms respond similarly in the recovery medium


The second speaker is Mr. Simon Shih who is program manager – Greater China, SABIC Innovative Plastics (former GE Plastics). He introduced the material varieties and common application requirement, common sterilization methods, biocompatibility and regulations, etc.

The typical market needs are identified:
- Clarity
- Sterilization
- Lipid / chemical resistance
- Biocompatibility, Food contact compliance
- Regulatory

Clarity: clear or transparent resins are often employed for device.
When: Fluid flow is visually
View of contents is required
Colorability for aesthetic enhancements

Sterilization:
1. Radiation
2. Stream Autoclave
3. Dry Heat Sterilization
4. Ethylene Oxide (EtO)
5. STERRAD® sterilization system (~1hr – very long cycle time!)

Lipid resistance (Fat) typically considered to drug or blood carriers. Typically exposure from 3 to 4 days but new treatment technology may be from 6 to 7 days.
Chemical resistance included disinfectants / cleaner (e.g. bleach, ammonia, ethyl ketone, IPA, etc.)

Regulation (WEEE/RoHS) &
Biocompatibility, Food Contact Compliance (US FDA and EU Regulation)

Test protocol / methods:
- ISO 10993: Test standards established by ISO & FDA
- USP Class VI: Test standards established by US Pharmacopoeia
- Both test protocols are still valid.