JAPANESE COMMENTS FOR CD 10993-18 (1998.1)

Dear Dr Keller,

I should like to ballot for CD 10993-18 by E-mail.
Formal sheet will be sent by air mail immediately.

We do not agree to the circulation of the draft as a DIS.

Attached please find the Japanese comments for ISO/CD 10993-18.

Akitada Nakamura, Ph.D.
Leader, Japanese Domestic Committee for ISO/TC194

GENERAL THOUGHTS

1. We suggest the revision of title, introduction and scope considering how and 
　in which situation do we use this part, and what can we standardize as a horizontal basis.

2. Regarding that this is a part of ISO 10993, the aspects of material characterization 
　(or identification or specification) should be discussed specifically in relation to 
　biological evaluation of materials and devices.

3. Necessary items and degree of characterization (or identification or specification) may 
　vary with varying kind of material (i.e.,metals, ceramics, polymers, or natural products) 
　and target device of different tissue contact and duration.  Therefore, it is rather difficult 
　to standardize the simple procedure universally applicable to every material and every 
　device purpose. The detail requirements of material characterization should be standardized 
　in a specific vertical standard such as contact lens, hip joint, and so forth.  
　However, we can describe the way of thinking.

4. For the purposes above, there could be several ways of material characterization, 
　specification, and identification : 
　　(i) preparing material master file (biomaterial compendium); 
　　(ii) standardization of each material such as titanium alloys in ISO/TC150; 
　　(iii) listing composition and additives, and manufacturing procedure if possible; and 
　　(iv) chemical, physical, and other testings.  
　These may be used independently or combined for the different puroposes 
　in different regulatory systems.

5. Judging equivalency between the material to be considered and the existing material of 
　clinical experience is critical to decide whether to perform tests or not, or in other 
　decisions such as substantial equivalence in new 510k in FDA reviewal and 
　equivalence between prototype and mass-production product, that is important in total 
　design management of medical devices.  
　Judging equivalency must be one of the major concern in this part.    

MORE DETAILED COMMENTS

1. We suggest to include the following clauses of several standards in "INTRODUCTION".

　　ISO 10993-1, Clause 6
             Annex A. A.2 Subclause 3.8

　　JAPANESE GUIDELINES: PRINCIPLES AND SELECTION OF TESTS
    　　　　 Clause 3.2) a) - e)

    FDA Notice of Substantial Equivalence (new 510k)

2. Add ISO/DIS 14538 as a normative reference.

3. We suggest to reword SCOPE including the GENERAL THOUGHTS above.

4. One practical idea for revision is limiting SCOPE to JUDGE EQUIVALENCE OF 
  MATERIAL with EXISTING MATERIAL, and to change TITLE to 
  "Specification, Identification and Characterization of Materials Needed in 
  Biological Equivalency."