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Tech News
Positive Control Material Introduced to ASTM Hemolysis Standard
The presence of hemolytic material in contact with the blood may
cause loss of, or damage to, red blood cells and may produce increased
levels of free plasma hemoglobin capable of inducing toxic effects
or other effects to the kidney or other organs. ASTM F 756, Standard
Practice for Assessment of Hemolytic Properties of Materials,
offers medical professionals a protocol for the assessment of
hemolytic properties of materials used in the fabrication of medical
devices that contact blood.
Last released in 1993, ASTM F 756 has undergone major revisions
including the addition of identifiable positive control materials
using only chemicals or hypotonic solutions. A task group has
been involved in the redraft for the past three years within Subcommittee
F04.16 on Biocompatibility Test Methods under Committee F-4 on
Medical and Surgical Materials and Devices. Participating in the
group are representatives from industry, the U.S. Food and Drug
Administration, and numerous contract labs. At this juncture,
the group has done extensive feasibility work and is accumulating
statistical information.
According to Task Group Chairman Regina Malczewski, Ph.D., a senior
research specialist and special testing and projects group leader
at Dow Corning Healthcare Industries, Midland, Mich., the task
group has assessed and challenged each part of the standard with
respect to viability and value. “It’s been a very interesting,
but challenging process. I want to make sure we have a standard
that is practical, and most importantly, that is sensitive enough.”
Significant revisions to ASTM F 756, as described by Subcommittee
F04.16 Chairman Katharine Merritt, Ph.D., are:
- A decrease in the concentration of blood used, thus greatly increasing
sensitivity;
- Identification of positive control materials;
- Change in sequence in which the parts of the standard are presented;
and
- Deletion of the standard techniques for measuring iron as an alternative
to measuring hemoglobin.
For further technical information, contact Regina Malczewski, Dow Corning Healthcare Industries Corp., Mail #C40D01, 2200
W. Salzburg Rd., Midland, MI 48686-0994 (517/496-4158; fax: 517/496-4654).
Committee F-4 next meets during ASTM Committee Week, May 24-26
in Toronto, Ontario, Canada. For meeting or membership information,
contact F-4 Staff Manager Teresa Cendrowska, ASTM (610/832-9718). //
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