ISCAGUARD ® Preservatives for Personal Care - ISCA UK Ltd

Preservatives available
from ISCA
Today, perhaps more than ever before, the safety of the
consumer has to be one of the most important concerns
when developing personal care products. For this reason
alone it is essential that cosmetics and toiletries are
protected from the unsightly and potentially hazardous
effects of microbial spoilage.
This is why ISCA offers a range of preservation solutions
based on tried and tested individual actives and
preservative blends.
This range includes:
• Parabens and their sodium salts
• 2-phenoxy ethanol
• Benzyl alcohol
• Imidazolidinyl and diazolidinyl urea
• Dimethyl dimethylol hydantoin (DMDMH)
• Chloromethyl/methyl isothiazolinone
• Liquid blends developed to optimise the
complementary properties of the individual actives.
Parabens and their
sodium salts
The antimicrobial efficacy of the esters of 4-hydroxy
benzoic acid was first discovered and patented in the
1920’s. Since that time they have become the most
frequently used, and, it is widely believed, safest
preservatives for personal care products.
The parabens are also available as their sodium salts,
which have the benefit of increased solubility in cold
water.
The list of benefits of the parabens includes;
• Broad spectrum of activity against bacteria and fungi
• Low order of toxicity
• Effectiveness at low concentrations
• Stability over a wide pH range
• Biodegradability at environmental concentrations
• Global acceptance in personal care formulations
ISCA Iscaguard ®
Preservative Blends 2
The paraben range available from ISCA is
highlighted below:
Iscaguard ®
M - methyl paraben
Iscaguard ®
E - ethyl paraben
Iscaguard ®
P - propyl paraben
Iscaguard ®
B - butyl paraben
Iscaguard ®
MS - sodium methyl paraben
Iscaguard ®
ES - sodium ethyl paraben
PS - sodium propyl paraben
Iscaguard ®
Regulatory Status
Paraben esters and their sodium salts are permitted for
use in personal care formulations in the US, Europe (total
paraben concentration maximum 0.8%) and Japan (total
paraben concentration maximum 1.0%).
Using paraben esters
Paraben esters may be added at any time during the
manufacturing process but it may be preferable to add
prior to any heating stage in order to facilitate good
mixing. They are more easily incorporated if pre-dissolved
in a solvent, such as propylene glycol. The sodium salts
can be added directly to cold aqueous mixes, but it is
important to subsequently adjust the pH, where
appropriate, as they exhibit a high pH.
Table 1
Solubility of paraben esters (% w/w @ 25°C)
Solvent M E P B MS ES PS
Water 0.25 0.11 0.04 0.02 33 50 50
Propylene glycol 26 20 29 49 ND ND ND
Ethanol
ND = no data
32 41 50 68 ND ND ND
Table 2
Antimicrobial activity of paraben esters
Microorganism Minimum inhibitory concentration (%)
M E P B MS ES PS
Pseudomonas aeruginosa 0.20 0.12 0.08 0.015 0.25 0.13 0.09
Escherichia coli 0.12 0.08 0.045 0.015 0.17 0.09 0.05
Proteus vulgaris 0.20 0.075 0.045 0.01 0.24 0.09 0.55
Staphylococcus aureus 0.16 0.12 0.045 0.015 0.20 0.14 0.05
Enterococcus faecium 0.15 0.10 0.06 0.015 0.20 0.10 0.06
Bacillus cereus 0.13 0.075 0.045 0.01 0.17 0.085 0.035
Candida albicans 0.10 0.06 0.025 0.015 0.14 0.075 0.035
Saccharomyces cerevisiae 0.08 0.045 0.025 0.015 0.11 0.05 0.025
Aspergillus niger 0.085 0.045 0.035 0.025 0.10 0.055 0.04