Synergistic preservative blends
A synergistic preservative composition comprises sorbic acid or a salt thereof, benzyl alcohol, and a mixture of (i) 1,2-propanediol and/or 1,3-propanediol, and (ii), 4-butanediol and/or 1,3-butanediol. The composition is particularly suited for the preservation of cosmetics and personal care products.
1. A preservative composition consisting essentially of
(a) from 1 to 6 wt. % of sorbic acid or a salt thereof;
(b) from 10 to 89 wt. % of benzyl alcohol;
(c) from 10 to 89 wt. % of a mixture of
(i) 1,2-propanediol, 1,3-propanediol, or a mixture thereof; and
(ii) 1,4-butanediol, 1,3-butanediol, or a mixture thereof
in a weight ratio of (i) to (ii) of 1:4 to 4:1,
based on the total weight of (a), (b) and (c).
2. The preservative composition of claim 1 , consisting essentially of
(a) from 1 to 4.5 wt. % of sorbic acid or a salt thereof,
(b) from 20 to 70 wt. % of benzyl alcohol,
(c) from 20 to 70 wt. % of a mixture of
(i) 1,2-propanediol, 1,3-propanediol, or a mixture thereof; and
(ii) 1,4-butanediol, 1,3-butanediol, or a mixture thereof,
in a weight ratio of (i) to (ii) of 1:4 to 4:1,
based on the total weight of (a), (b) and (c).
3. The preservative composition of claim 2 , wherein component (c) is a mixture of (i) 1,2-propanediol and (ii) 1,4-butanediol.
4. The preservative composition of claim 2 , wherein component (c) is a mixture of (i) 1,3-propanediol and (ii) 1,3-butanediol.
5. The preservative composition of claim 1 , wherein component (c) is a mixture of (i) 1,2-propanediol and (ii) 1,4-butanediol.
6. The preservative composition of claim 5 , consisting essentially of
(a) from 1 to 6 wt. % of sorbic acid,
(b) from 20 to 45 wt. % of benzyl alcohol,
(c) from 50 to 70 wt. % of a mixture of
(i) 1,2-propanediol; and
(ii) 1,4-butanediol,
in a weight ratio of (i) to (ii) of 1:4 to 2:1,
based on the total weight of (a), (b) and (c).
7. The preservative composition of claim 1 , wherein component (c) is a mixture of (i) 1,3-propanediol and (ii) 1,3-butanediol.
8. The preservative composition of claim 7 , consisting essentially of
(a) from 1 to 6 wt. % of sorbic acid,
(b) from 20 to 45 wt. % of benzyl alcohol,
(c) from 50 to 70 wt. % of a mixture of
(i) 1,3-propanediol; and
(ii) 1,3-butanediol,
in a weight ratio of (i) to (ii) of 1:4 to 2:1,
based on the total weight of (a), (b) and (c).
9. The preservative composition of claim 1 , consisting essentially of
(a) from 1 to 6 wt. % of sorbic acid or a salt thereof;
(b) from 10 to 89 wt. % of benzyl alcohol;
(c) from 10 to 89 wt. % of a mixture of
(i) a propanediol consisting of 1,2-propanediol; and
(ii) a butanediol comprising 1,4-butanediol, 1,3-butanediol, or a mixture thereof;
in a weight ratio of (i) to (ii) of 1:4 to 4:1,
based on the total weight of (a), (b) and (c).
10. The preservative composition of claim 1 , consisting essentially of
(a) from 2 to 6 wt. % of sorbic acid or a salt thereof;
(b) from 20 to 45 wt. % of benzyl alcohol;
(c) from 50 to 89 wt. % of a mixture of
(i) 1,2-propanediol, 1,3-propanediol, or a mixture thereof; and
(ii) 1,4-butanediol, 1,3-butanediol, or a mixture thereof
in a weight ratio of (i) to (ii) of 1:4 to 2:1,
based on the total weight of (a), (b) and (c).
11. The preservative composition of claim 1 , consisting essentially of
(a) from 1 to 6 wt. % of sorbic acid or a salt thereof;
(b) from 20 to 30 wt. % of benzyl alcohol;
(c) from 65 to 75 wt. % of a mixture of
(i) 1,2-propanediol; and
(ii) 1,4-butanediol;
in a weight ratio of (i) to (ii) of 1:4 to 4:1,
based on the total weight of (a), (b) and (c).
12. The preservative composition of claim 1 , wherein the composition exhibits a mixed fungi germ count of less than 10 cfu/g within 28 days during a challenge test wherein the mixed fungi contain Candida albicans and Aspergillus niger.
13. A preservative composition consisting of
(a) from 1 to 6 wt. % of sorbic acid or a salt thereof,
(b) from 10 to 89 wt. % of benzyl alcohol,
(c) from 10 to 89 wt. % of a mixture of
(i) 1,2-propanediol, 1,3-propanediol, or a mixture thereof; and
(ii) 1,4-butanediol, 1,3-butanediol, or a mixture thereof,
in a weight ratio of (i) to (ii) of 1:4 to 4:1,
based on the total weight of (a), (b) and (c), and
(d) optionally one or more solvents, anti-oxidants, stabilizers, colorants, fragrances, and perfumes.
14. The preservative composition of claim 13 , consisting of
(a) from 1 to 4.5 wt. % of sorbic acid or a salt thereof,
(b) from 20 to 45 wt. % of benzyl alcohol,
(c) from 50 to 70 wt. % of a mixture of
(i) 1,2-propanediol, 1,3-propanediol, or a mixture thereof; and
(ii) 1,4-butanediol, 1,3-butanediol, or a mixture thereof,
in a weight ratio of (i) to (ii) of 1:4 to 2:1,
based on the total weight of (a), (b) and (c), and
(d) optionally one or more solvents, anti-oxidants, stabilizers, colorants, fragrances, and perfumes.
15. The preservative composition of claim 13 , wherein component (c) is a mixture of (i) 1,2-propanediol and (ii) 1,4-butanediol.
16. The preservative composition of claim 13 , wherein component (c) is a mixture of (i) 1,3-propanediol and (ii) 1,3-butanediol.
17. A method for inhibiting microbial growth in a cosmetic or personal care product, comprising the step of adding to said product a preservative composition according to claim 1 in an amount of 0.1 to 10.0 wt. %, calculated as sum of components (a), (b) and (c), and based on 100% total weight of said product.
18. The method of claim 17 , wherein the preservative composition is added to the cosmetic or personal care product in an amount of 0.5 to 5.0 wt. %, calculated as sum of components (a), (b) and (c), and based on 100% total weight of said product.
19. The method of claim 17 , wherein the cosmetic or personal care product is selected from the group consisting of shampoos, lotions, shower gels, bubble baths, bath oils, creams, baby products, liquid soaps, hair gels, make-up, and sunscreens.
20. A preserved cosmetic or personal care product obtained by the method of claim 17 .
21. A method for inhibiting microbial growth in a cosmetic or personal care product, comprising the step of adding to said product a preservative composition according to claim 14 in an amount of 0.1 to 10.0 wt. %, calculated as sum of components (a), (b) and (c), and based on 100% total weight of said product.
22. The method of claim 21 , wherein the preservative composition is added to the cosmetic or personal care product in an amount of 0.5 to 5.0 wt. %, calculated as sum of components (a), (b) and (c), and based on 100% total weight of said product.
23. The method of claim 21 , wherein the cosmetic or personal care product is selected from the group consisting of shampoos, lotions, shower gels, bubble baths, bath oils, creams, baby products, liquid soaps, hair gels, make-up, and sunscreens.
24. A preserved cosmetic or personal care product obtained by the method of claim 21 .