TPE medical materials need to come into contact with human tissues, blood, body fluids, and some may even be permanently implanted in the body. Therefore, such materials must have excellent biological substitutability (mechanical properties, functionality), biocompatibility, and blood compatibility.

Thermoplastic elastomers also need to meet the following basic conditions:

(1) It is chemically inert and will not react due to contact with body fluids:

(2) Does not cause inflammation and foreign body reactions to human tissues;

(3) Not carcinogenic;

(4) No allergic reactions will occur;

(5) Having good blood compatibility, non hemolysis, non coagulation;

(6) Long term implantation into the body will not result in loss of physical and mechanical properties such as tensile strength and elasticity;

(7) Able to withstand necessary disinfection measures without deformation;

(8) Easy to process into the desired and complex shapes.

1、 Standards for medical devices

1. USP United States Pharmacopoeia

The US Pharmacopoeia is a technical regulation made by the US government on drug quality standards and testing methods, and is also the legal basis for drug production, use, management, and testing. NF contains new drugs and formulations that have not yet been included in the United States Pharmacopoeia (USP).

2. EP European Pharmacopoeia

The European Pharmacopoeia is the only guiding document for drug quality testing in Europe. All manufacturers of drugs and pharmaceutical substrates must comply with the quality standards of the European Pharmacopoeia during their promotion and use within Europe.

http://3.JP Japanese Pharmacopoeia

Compiled by the Editorial Committee of the Japanese Pharmaceutical Bureau and promulgated and implemented by the Ministry of Health and Welfare of Japan. Published in two parts, the first part covers raw materials and their basic preparations, while the second part mainly covers raw materials, family drug preparations, and preparation materials.

4. International Pharmacopoeia

The International Pharmacopoeia is compiled and published by the World Health Organization (WHO), abbreviated as Ph. Int., for free use by WHO member states. Many countries, especially African member states, use the International Pharmacopoeia as their recognized standard, which has legal effect.

5. British Pharmacopoeia

It is the official set of medical standards published by the UK Medicines Commission, an important source of UK pharmaceutical standards, and an important basis for drug quality control and drug production license management.

6. FDA

The abbreviation for the Food and Drug Administration. The FDA sometimes represents the United States FDA, also known as the Food and Drug Administration. The FDA is an international medical review authority authorized by the United States Congress, the federal government, and is the highest law enforcement agency specializing in food and drug management; Many other countries seek and receive assistance from the FDA to promote and monitor the safety of their domestic products.

7. YY/T 0316-2008/ISO 14971:2007

The requirements contained in this standard provide a framework for manufacturers to systematically apply experience, insights, and judgments to manage risks related to the use of medical devices. This standard is specifically developed for manufacturers of medical devices/systems used to establish risk management principles.

8. ISO13485

ISO13485, also known as "Medical Device Quality Management System" in Chinese, is a special product for saving lives, helping injuries, and preventing and treating diseases. It is not enough to standardize medical devices solely according to the general requirements of ISO9000 standards. Therefore, ISO has issued ISO13485, which is a management standard for the company's factory, not for the materials themselves.

9. ISO10993/GB16886

ISO10993/GB16886 is an international and domestic biological evaluation standard for medical devices

10. GB 15593-1995 Flexible polyvinyl chloride plastics for blood (liquid) transfusion equipment

This standard is for PVC materials that were extensively used before, so SEBS is not applicable.

2、 Classification of medical devices - Contact properties

1. Surface contact device

a) Skin: Instruments that only come into contact with the surface of undamaged skin; Such as various types of electrodes, extracorporeal prostheses, fixation straps, compression bandages, and monitors;

b) Mucosa: Instruments that come into contact with the mucosa; Such as contact lenses, catheters, * * internal or gastrointestinal instruments (gastric tubes, sigmoidoscopy, colonoscopy, gastroscopy), endotracheal tubes, bronchoscopy, dentures, orthodontic appliances, and intrauterine contraceptives;

c) Damaged surface: Instruments that come into contact with wounds or other damaged body surfaces; Such as ulcers, burns, granulation tissue dressings or healing instruments, wound dressings, etc.

2. External access devices

a) An instrument that comes into contact with a certain point on the bloodstream and serves as a conduit for input into the vascular system; Such as infusion devices, extenders, transfer devices, blood transfusion devices, etc;

b) Instruments and materials in contact with tissues, bones, and pulp/dentin systems; Such as laparoscopy, joint endoscopy, drainage system, dental cement, dental filling materials, and skin hooks;

c) Devices that come into contact with circulating blood; Such as intravascular catheters, temporary pacemaker electrodes, oxygenators, extracorporeal oxygenator tubes and accessories, dialyzers, dialysis tubes and accessories, blood adsorbents and immunosorbents.

3. Implant devices, including devices that come into contact with the following application areas

(1) Tissue/Bone

(a) Instruments that mainly come into contact with bone, such as orthopedic nails, orthopedic plates, artificial joints, bone prostheses, bone cement, and intraosseous instruments;

(b) Devices that mainly come into contact with tissues and tissue fluids, such as pacemakers, drug delivery devices, neuromuscular sensors and stimulators, artificial tendons, breast implants, artificial throats, subperiosteal implants, and ligature clips;

(2) Blood

Instruments primarily in contact with blood; Such as pacemaker electrodes, artificial arteriovenous fistulas, heart valves, vascular grafts, in vivo drug release catheters, and ventricular assist devices.

3、 Classification of medical devices - Exposure time

1. Short term exposure (A): Equipment that has been in contact for less than 24 hours once or multiple times;

2. Long term exposure (B): Single, multiple, or long-term use of equipment that has been in contact for more than 24 hours but less than 30 days;

3. Persistent exposure (C): Devices that have been in contact for more than 30 days after one, multiple, or long-term use.

If a material or device belongs to two or more time classifications, it is recommended to implement stricter testing requirements. For devices that have been used multiple times, it is recommended to consider the potential cumulative effects and classify the devices based on the total time of exposure.