ISCAGUARD ® Preservatives for Personal Care - ISCA UK Ltd

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It can be used over a wide pH range, from 3.0 or lower,
up to 8.0 and should be added during the cooling stage
of any hot process.
Regulatory Status
Iscaguard ®
CMI is approved for use in the US (up to a
maximum of 0.1% in rinse-off products and 0.05% in
leave-on products) Europe (up to a maximum of 0.1%)
and Japan (up to a maximum of 0.1% in rinse-off
products only).
Table 12
Antimicrobial activity of Iscaguard ®
CMI
Microorganism Minimum inhibitory
concentration(%)
Pseudomonas aeruginosa 0.03
Staphylococcus aureus 0.02
Candida albicans 0.03
Aspergillus niger 0.06
Liquid blends developed to
optimise the complementary
properties of the individual
actives
Although successful preservation can be achieved by
using single-component preservatives, we at ISCA believe
that it can often be achieved more effectively and more
safely, through the use carefully designed preservative
blends.
Why Blends?
An ideal preservative system must be:
• Effective (i.e. have a broad spectrum of activity)
• Safe to use
• Safe at use levels
• Stable in the product
• Compatible with the product and packaging
It is rare to find a single preservative that meets all of the
above requirements. Most preservatives have their plus
points, but they usually also have some negatives
associated with their use. However, if we stop thinking
about “The Preservative”, and start thinking about “The
Preservation System”, we can minimise the negatives
and accentuate the positives.
One further consideration is that of time. Preserving a
formulation using separate components can be time
consuming. If the product fails the microbial challenge
ISCA Iscaguard ®
Preservative Blends
test, the next stage of development can involve adding
an extra component to combat the organisms that caused
the initial failure. The revised preservative system may
also fail the challenge test, resulting in still more
preservative being added. This unfocussed strategy can
result in too many preservatives at too high a
concentration, and a significant delay for the product
launch with all the associated cost implications.
The process may be simplified by testing a broadspectrum
preservative blend over a range of
concentrations. This strategy, if correctly employed, can
usually result in a challenge test pass at the first attempt,
and at a concentration reasonably close to the optimum
for that particular formulation. Closer optimisation can be
achieved by testing two or more different blends.
For all these reasons, ISCA offers a range of preservative
blends with all the advantages we can put in there.
These products have been carefully developed to give a
combination of preservatives in which the ratio of
components is closest to the optimum activity for as
many different formulations as possible.
An example of a
preservation strategy
Better optimisation of the preservative system in a
product may be achieved by testing many different
preservatives, or preservative blends, over a broad range
of concentrations. It is often difficult, however, to justify
submission of more than 5 or 6 different options for
challenge testing. On this basis, a general example of a
possible preservation strategy is given below:
Submit samples containing the following preservative
blends:
Iscaguard ®
Iscaguard ®
MPB @ 0.3, 0.6 and 1.0%
PBA @ 0.3 and 0.6%
The results will indicate which of the blends is the more
effective in the product under test. Iscaguard ®
MPB is
included at 1.0% to try to ensure that at least one
preservative treatment passes the challenge test, even if
the lower concentrations fail. This strategy makes it more
likely that the product can be launched without delay
and, if the highest concentration is the only successful
one, lower concentrations (in this example, 0.7, 0.8 and
0.9%) could be tested after launch to establish whether a
reduction in the preservative concentration is possible.