Biomedical Engineering Reference
In-Depth Information
which is slightly different and occasionally requires modifi cation of testing
requirements and plans. This is the G95-1 ('Blue Book') Memorandum.
In May 1995 the Offi ce of Device Evaluation (ODE) adopted General
Program Memorandum G95-1, an FDA-modifi ed version of International
Standard ISO 10993, 'Biological Evaluation of Medical Devices Part I', spe-
cifi cally requiring individual organ or system toxicity evaluation. Table 9.3
forms the core of G95-1.
Specifi c additional or clarifying points include:
1. For those devices with possible leachables or degradation products, e.g.
absorbable surfaces, haemostatic agents, etc., testing for pharmacokinet-
ics may be required.
2. Reproductive and developmental toxicity tests may be required for cer-
tain materials used for specialized indications.
3. Consideration should be given to long-term biological tests where indi-
cated in the table, taking into account the nature and mobility of the
ingredients in the materials used to fabricate the device.
A typical test matrix set to meet these requirements for an implantable
device is presented in Table 9.4 .
9.4.1 Topical devices
These devices are most commonly drug delivery systems (such as transder-
mal patches) that are part of a combination product, or a wound dressing.
Table 9.5 summarizes the test requirements.
9.4.2 Blood path direct
This special class of devices includes such things as stents (bare metal or
drug-coated), catheters and
in situ
primary artery repair systems and
requires the studies summarized in Table 9.6. However, if component mate-
rials are present that add the possibility of releasing dangerous degradation
products or impurities into the blood stream, testing to address these possi-
bilities is also required.
9.4.3 Bone and tissue (orthopedic, dental, non-vascular
tissue)
These include a broad assortment of devices, many of which (such as
orthopedic devices that include pins and replacements for bone joints)
require use of unusual species (sheep and goats) for biocompatibility due
to issues of scale. Note that synthetic products, such as dental wires for
