ISCAGUARD ® Preservatives for Personal Care - ISCA UK Ltd

9
Iscaguard ®
LIN
Iscaguard ®
LIN is a strongly synergistic blend of
methyldibromo glutaronitrile, bronopol, phenoxyethanol,
butylparaben and isobutylparaben giving the advantages
of broad-spectrum antimicrobial protection and ease of
liquid handling.
The synergistic activity of Iscaguard ®
LIN allows very low
use concentrations (typically between 0.03 – 0.15%). This
activity is similar to that of isothiazolinone-based
preservatives.
The low concentrations required of Iscaguard ®
LIN
enhance the safety profile of the product, as much lower
concentrations of the individual components are present
in the final product compared to normal usage. When
using Iscaguard ®
LIN, the concentration of bronopol, for
example, is reduced by a factor of between 5 – 12.
This substantial reduction in bronopol concentrations has
critical implications for nitrosamine formation in products
containing amines. At normal bronopol use concentrations
(200 – 400ppm), there is an increase in the potential for
nitrosamine formation when amines are present.
Evidence suggests, however, that nitrosamine formation
is not detectable in formulations containing both
Iscaguard ®
LIN and amines such as triethanolamine and
stearamidopropyl dimethylamine, even after prolonged
storage. Iscaguard ®
LIN may, therefore, be used in
amine-based formulations, although testing to confirm
the absence of nitrosamines is strongly recommended.
Iscaguard ®
LIN is effective over the range pH 3.0 – 7.5 and
is non-irritating to eyes, skin and mucous membranes at
the recommended use concentrations.
Iscaguard ®
LIN retains its activity in the presence of
proteins and nonionic emulsifiers.
ISCA Iscaguard ®
Preservative Blends
Regulatory Status
Iscaguard ®
LIN is permitted for use in rinse-off products in
the European Union (maximum 0.77%) and the USA
(maximum 0.77%). Iscaguard ®
LIN is not permitted for
use in Japan.
INCI name: phenoxyethanol, methyldibromo glutaronitrile,
2-bromo-2-nitropropane-1,3-diol, butylparaben,
isobutylparaben.
Using Iscaguard ®
LIN
Iscaguard ®
LIN is soluble in water to approximately
0.4% – significantly greater than the typical use
concentrations – but it is preferable to pre-dissolve the
product in a non-aqueous component prior to addition.
This avoids the need to heat Iscaguard ®
LIN, as the
product should not be exposed to temperatures above
40°C for prolonged periods.
Iscaguard ®
LIN may discolour on exposure to UV light and
should be stored in the original container.
Table 21
Solubility of Iscaguard ®
LIN (% w/w @ 25°C)
Water Approx. 0.4%
Propylene glycol Miscible
Butylene glycol Miscible
Table 22
Antimicrobial activity of Iscaguard ®
LIN
Microorganism Minimum inhibitory
concentration (%)
Pseudomonas aeruginosa 0.035
Escherichia coli 0.025
Proteus vulgaris 0.0175
Staphylococcus aureus 0.03
Bacillus cereus 0.0275
Enterococcus faecium 0.035
Candida albicans 0.0125
Saccharomyces cerevisiae 0.0125
Aspergillus niger 0.04