Use of cationic surfactants in cosmetic preparations

Description

RELATED APPLICATION DATA

This application is a national phase application under 35 U.S.C. 371 of PCT/EP01/09198, filed Aug. 9, 2001.

FIELD OF THE INVENTION

This invention relates to a novel use of cationic surfactants and preparations according to this novel use.

BACKGROUND OF THE INVENTION

Due to their composition, many cosmetic products are susceptible to act as a culture medium for microorganisms, and this can cause possible alterations to the cosmetic preparation and constitute a possible risk to human heath as well. Thus, a cosmetic composition requires good protection against microbiological contamination.

A well-known substance used for the protection against microorganisms is a cationic surfactant derived from lauric acid and arginine, in particular, the ethyl ester of the lauramide of the arginine monohydrochloride, hereafter named LAE. The chemical structure is described in the following formula:

This compound is remarkable for its activity against different microorganisms, such as bacteria, fungi and yeasts and its use is known in food and feed preparations. The compound is well-known to be harmless to animals and humans. The minimum inhibitory concentrations of LAE are shown in the following table 1.

TABLE 1
		M.I.C.
Kind	Microorganism	(ppm)

Gram + Bacteria	Arthrobacter oxydans ATCC 8010	64
	Bacillus cereus var mycoide ATCC 11778	32
	Bacillus subtilis ATCC 6633	16
	Clostridium perfringens ATCC 77454	16
	Listeria monocytogenes ATCC 7644	10
	Staphylococcus aureus ATCC 6538	32
	Micrococcus luteus ATCC 9631	128
	Lactobacillus delbrueckii ssp lactis CECT 372	16
	Leuconostoc mesenteroides CETC 912	32
Gram − Bacteria	Alcaligenes faecalis ATCC 8750	64
	Bordetella bronchiseptica ATCC 4617	128
	Citrobacter freundii ATCC 22636	64
	Enterobacter aerogenes CECT 689	32
	Escherichia coli ATCC 8739	32
	Escherichia coli 0157H7	20
	Klebsiella pneumoniae var pneumoniae	32
	CECT 178
	Proteus mirabilis CECT 170	32
	Pseudomonas aeruginosa ATCC 9027	64
	Salmonella typhimurium ATCC 16028	32
	Serratia marcenses CECT 274	32
	Mycobacterium phlei ATCC 41423	2
Fungi	Aspergillus niger ATCC 14604	32
	Aureobasidium pullulans ATCC 9348	16
	Gliocadium virens ATCC 4645	32
	Chaetonium globosum ATCC 6205	16
	Penicillium chrysogenum CECT 2802	128
	Penicillium funiculosum CECT 2914	16
Yeast	Candida albicans ATCC 10231	16
	Rhodotorula rubra CECT 1158	16
	Saccharomyces cerevisiae ATCC 9763	32

DETAILED DESCRIPTION

It has now been detected that the product LAE and related compounds are particularly suitable to be used in cosmetic preparations.

The use of the invention relates to cationic surfactants derived from the condensation of fatty acids and esterified dibasic amino acids, according to the following formula:

where:
X⁻ is Br⁻, Cl⁻, or HSO₄⁻
R₁: is a linear alkyl chain from a saturated fatty acid or hydroxyacid from 8 to 14 atoms of carbon bonded to the α-amino acid group through an amidic bond.
R₂: is a linear or branched alkyl chain from 1 to 18 carbon atoms or an aromatic group.
R₃: is:

and n can be from 0 to 4.

The most preferred compound of the above class of compounds is LAE.

LAE can be used in cosmetic formulations and preparations that are applied in the epidermis, the capillary system, lips, nails, external genital organs, or in the teeth and mouth cavity mucous, in order to clean, perfume, or modify its aspect and/or change corporal smells and/or protect a good physical fitness. At the same time LAE inhibits the growth of microorganisms in the cosmetic formulations and preparations in which they are susceptible to develop, and also from the microorganisms that can be introduced by the practical use of the customer.

The compositions of the invention have a medium which is compatible with the skin, the mucous membranes, and hair. These compositions can have the classical components such as: fatty compounds such as mineral oil, animals oil, vegetal oil, synthesis and silicon oils, and also alcohols, fatty acids and waxes; organic solvents, surface active agents, solubilizers and ionic and non ionic emulsifiers, thickening agents and jellying hydrophilic agents such as carboxyvinylic polymers (e.g. carbomer), acrylic copolymers (e.g. acrylates and alkylacrylates), polyacrylamides, polysaccharides, natural gums (e.g. xanthan gum); thickening agents and jellying lipophilic agents such as modified clays (e.g. bentonite), fatty acid metallic salts, hydrophobic silica and polyethylene; perfumes and essential oils; softening agents; excipients; antioxidants; sequestering agents; opacifiers; filters; colouring compounds which may be either hydrosoluble or liposoluble, and pigments; and hydrophilic or lipophilic active ingredients. These compositions can also contain further preservatives besides the ones used according to the invention.

The proportions of the components mentioned in the previous paragraph are the ones normally used in the mentioned applications. These components have to be applied without changing the preservative system of the invention.

According to the invention the compositions can be in different cosmetic forms suitable for a topic application, such as:

• • a) Monophasic systems:
    • Aqueous or hydroglycolic solution that contain one or more surfactants to be used for the cleaning of the skin, hair and mucous membranes;
    • Aqueous, hydroalcoholic, hydroglycolic or oily solution that can contain other additives to be used in the general care and/or protection for skin and/or mucous membranes;
    • Aqueous, hydroalcoholic, hydroglycolic or oily gel that can contain other additives to be used in general care and/or protection for skin and/or mucous membranes;
    • Solid anhydride products that can contain other additives to be used in the general care and/or protection for skin and/or mucous membranes;
  • b) Biphasic systems:
    • Aqueous, hydroalcoholic, hydroglycolic or oily gel that can contain other additives to be used in general care and/or protection for skin and/or mucous membranes;
    • Solid anhydride products that can contain other additives to be used in the general care and/or protection for skin and/or mucous membranes;
    • Emulsions formed by dispersion of a oil phase in a water phase (O/W) or inverse phase (W/O), to be used in general care and/or protection of the face skin, body, hands and/or mucous; cleaning and/or removal of make-up from the skin, mucous membranes, hair and/or mouth cavity; protection and/or skin care against solar radiation effects; colouring support and pigment to be applied to the skin.
  • c) And combinations of the other systems that form multiphasic systems, suspensions and microemulsions.

The compositions previously mentioned can be used in different forms such as foam, spray, or aerosol compositions and can contain a propulsion agent under pressure.

Thus, the compositions of the invention can have the aspect of a cream, a lotion, a milk, an emulsion, a gel or an oil for the skin, a beauty mask, a salt, a gel, a foam/spray or an oil for bath and shower, or for making up and making-up cleaner for the face and eyes and any other aspect known in the art.

The compositions according to the invention have been prepared according to the techniques well known for a person skilled in the art.

Procedure to Evaluate the Preservative Efficacy for LAE

The method is based on the Antimicrobial Effectiveness Testing USP 24^th Edition, 1999 (pp. 1809-1811), in order to demonstrate that the antimicrobial activity of the compound aim of the patent is enough to avoid the microbial growth that could have in the storage and use of the preparation, preventing the adverse effects of the contamination (Real Farmacopea Española, 1^st Edición, 1997).

This assay consists of the contamination of the protecting formulations with an inoculum mixture of 10⁸ cfu/mL concentration, for each of the microorganisms, and the determination of the number of viable cells in the time. This inoculum mixture is composed of the following microorganisms:

	Pseudomonas aeruginosa	ATCC 9027
	Staphylococcus aureus	ATCC 6538
	Candida albicans	ATCC 10231
	Aspergillus niger	ATCC 16404
	Escherichia coli	ATCC 8739

The cosmetic composition to be analysed is divided into sterile containers with 50 g of product for each flask. Each container is inoculated with 0.5 mL of inoculum (10⁸ cfu/mL). The target concentration is 10⁶ cfu/mL, approximately. All the containers are kept at a temperature between 20-25° C. and are protected from light.

The level of the microbial contamination is checked at 0 hours, 7 days, 14 days and 28 days. The number of colonies is evaluated by dilution in buffer peptone with the appropriate neutraliser agent of the preservative. The culture media used for counting the microorganisms are: Soya triptone (35-37° C., 48 hours) for the determination of bacteria; Sabouraud agar with chloramphenicol for fungi and yeast (25° C., 3-5 days).

According to Antimicrobial Effectiveness Testing USP 24^th Edition, 1999 (pp. 1809-1811), an antimicrobial preservative is considered to be effective in topically used products made with aqueous bases or vehicles, non-sterile nasal products and emulsions, including those applied to mucous membranes, if:

• • Not less than 2.0 logarithm reduction from the initial calculated bacteria's count is reached at 14 days and no increase from the 14 days' count at 28 days is detected; and
  • No increase from the initial calculated count of yeast and moulds is observed.

EXAMPLES

Different examples of cosmetic preparations and formulations are provided where the product has been assayed. Theses examples are a part of the preparations and formulations assayed.

Example 1

The composition of the cosmetic formulation in oil-in-water emulsion with non-ionic surfactant, is (in g):

	Polysorbate 60	3.00
	Sorbitan stearate	2.00
	Cetyl alcohol	1.00
	Paraffinum	3.00
	Isopropyl mirystate	3.00
	Caprylic-caproic triglycerides	3.00
	Dimethicone	0.50
	Propylene glycol	3.00
	Cellulose gum	0.25
	Carbomer 940	0.10
	Triethanolamine	0.10
	Aqua	100	c.s.p.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the table 2.

TABLE 2
				With
			Without LAE	LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	2.1 · 106	1.1 · 106
		Fungi	1.6 · 104	1.7 · 104
		Yeast	3.7 · 105	5.6 · 105
	7 days	Aerobes	2.1 · 106	3.1 · 103
		Fungi	7.0 · 102	<9.9 · 101
		Yeast	8.2 · 103	9.5 · 102
	14 days	Aerobes	6.2 · 106	3.3 · 102
		Fungi	5.9 · 102	<9.9 · 101
		Yeast	4.8 · 103	4.0 · 102

At 28 days no increase has been detected from the 14 days' count.

Example 2

The composition of an oil-in-water emulsion with an ionic emulsifier, used as cosmetic formulation, is (in g):

	Stearic acid	1.70
	Glyceryl stearate S.E.	2.50
	Cetyl alcohol	1.50
	Paraffinum	3.00
	Isopropyl myristate	3.00
	Caprylic-caproic triglycerides	3.00
	Dimethicone	0.50
	Propylene glycol	3.00
	Cellulose gum	0.50
	Triethanolamine	1.03
	Aqua	100	c.s.p.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the table 3.

TABLE 3
				With
			Without LAE	LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	7.4 · 106	2.7 · 106
		Fungi	2.0 · 104	1.4 · 104
		Yeast	3.6 · 104	3.6 · 104
	7 days	Aerobes	5.2 · 106	1.6 · 104
		Fungi	8.8 · 102	<9.9 · 101
		Yeast	4.7 · 104	1.0 · 102
	14 days	Aerobes	1.7 · 107	6.5 · 102
		Fungi	7.0 · 102	<9.9 · 101
		Yeast	1.0 · 104	1.0 · 102

At 28 days no increase has been detected from the 14 days' count.

Example 3

The general composition for a cosmetic formulation, in water in oil emulsion with non-ionic emulsifiers, is (in g)

	Cetyl Dimethicone copolyol	3.00
	Isohexadecane	6.00
	Paraffinum	8.00
	Isopropyl myristate	6.00
	Caprylic-caproic triglycerides	4.00
	Glycerin	5.00
	Sodium chloride	0.50
	Aqua	100	c.s.p.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the Table 4.

TABLE 4
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	1.6 · 106	6.2 · 106
		Fungi	2.0 · 104	1.0 · 104
		Yeast	3.8 · 104	7.0 · 104
	7 days	Aerobes	1.1 · 106	1.8 · 103
		Fungi	5.0 · 102	<9.9 · 101
		Yeast	9.0 · 102	<9.9 · 101
	14 days	Aerobes	8.7 · 106	<9.9 · 101
		Fungi	3.0 · 102	<9.9 · 101
		Yeast	3.0 · 102	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 4

The composition of a formulation to obtain an aqueous solution with a surfactants' mixture, is (in g):

	Sodium lauryl sulfate (sol. 27%)	14.00
	Cocamidopropyl betaine	6.00
	Disodium cocoamfoacetate	6.00
	Lactic acid	0.25
	Sodium chloride	0.50
	Aqua	100	c.s.p.

This formulation is applied in bath gels.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the Table 5.

TABLE 5
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	3.6 · 106	3.3 · 106
		Fungi	1.6 · 104	1.9 · 104
		Yeast	3.9 · 104	4.6 · 104
	7 days	Aerobes	4.2 · 106	5.8 · 103
		Fungi	2.7 · 103	2.7 · 102
		Yeast	4.5 · 103	<9.9 · 101
	14 days	Aerobes	5.5 · 106	<9.9 · 101
		Fungi	3.4 · 103	<9.9 · 101
		Yeast	5.9 · 103	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 5

The composition of a formulation to obtain an aqueous solution with a surfactants' mixture, is (in g):

	Sodium lauryl sulfate (sol. 27%)	14.00
	Cocamidopropyl betaine	6.00
	Disodium lauryl sulfosuccinate	6.00
	Lactic acid	0.25
	Sodium chloride	0.50
	Aqua	100	c.s.p.

This formulation is applied in bath gels.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the Table 6.

TABLE 6
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	8.6 · 106	6.7 · 106
		Fungi	1.1 · 104	1.4 · 104
		Yeast	3.2 · 104	3.6 · 104
	7 days	Aerobes	3.9 · 107	4.8 · 102
		Fungi	1.6 · 103	<9.9 · 101
		Yeast	3.1 · 103	<9.9 · 101
	14 days	Aerobes	3.3 · 106	1.3 · 102
		Fungi	8.3 · 103	<9.9 · 101
		Yeast	3.9 · 104	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 6

The composition of a formulation to obtain a hydroalcoholic gel, is (in g):

	Hydroxyethyl cellulose	0.40
	Carbomer 940	0.40
	Glycerin	8.00
	Alcohol denat	30.00
	PEG 40 hydrogenated castor oil	1.50
	Parfum	0.75
	Triethanolamine	0.25
	Aqua	100	c.s.p.

This formulation is applied in lotions for after-shaving skin care.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the Table 7.

TABLE 7
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	1.1 · 106	3.7 · 106
		Fungi	8.7 · 104	9.1 · 104
		Yeast	3.9 · 104	4.2 · 104
	7 days	Aerobes	4.6 · 106	6.9 · 103
		Fungi	9.1 · 103	4.1 · 102
		Yeast	8.6 · 102	1.6 · 102
	14 days	Aerobes	7.3 · 106	<9.9 · 101
		Fungi	1.7 · 103	<9.9 · 101
		Yeast	1.2 · 103	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 7

The composition of a formulation to obtain a facial tonic, is (in g):

	Hydroxyethyl cellulose	0.20
	Caprylic-caproic triglycerides	1.00
	PEG 40 hydrogenated castor oil	6.00
	Lactic acid	1.00
	Sodium chloride	0.35
	Glycerin	3.00
	Chamomilla Recutita extract	3.00
	Aqua	100	c.s.p.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the Table 8.

TABLE 8
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	6.7 · 106	2.7 · 106
		Fungi	4.1 · 104	2.1 · 104
		Yeast	3.2 · 104	1.2 · 104
	7 days	Aerobes	3.7 · 107	3.6 · 103
		Fungi	9.1 · 103	1.3 · 102
		Yeast	4.2 · 103	1.1 · 102
	14 days	Aerobes	8.7 · 107	5.9 · 102
		Fungi	2.1 · 104	<9.9 · 101
		Yeast	1.2 · 104	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 8

The composition of a formulation to obtain a mask-up cleaner, is (in g):

	Stearic acid	2.00
	Glyceryl stearate S.E	2.50
	Cetyl alcohol	1.50
	Paraffinum	6.00
	Isopropyl myristate	1.50
	Caprylic-caproic triglycerides	1.50
	Dimethicone	0.50
	Propylene glycol	3.00
	Triethanolamine	1.20
	Aqua	100	c.s.p.

This formulation is completed with 0.20 g of LAE, and the preservative capacity is evaluated and it is compared with the formulation without LAE. The results are shown in the Table 9.

TABLE 9
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	5.5 · 106	4.5 · 106
		Fungi	7.9 · 104	7.6 · 104
		Yeast	8.4 · 104	7.2 · 104
	7 days	Aerobes	6.5 · 106	3.8 · 103
		Fungi	8.2 · 102	3.5 · 102
		Yeast	8.8 · 102	1.8 · 102
	14 days	Aerobes	9.5 · 106	6.7 · 102
		Fungi	2.9 · 103	<9.9 · 101
		Yeast	1.8 · 103	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 9

The composition of a formulation to obtain a fluid oil-in-water emulsion with non-ionic surfactants, is (in g):

	Polysorbate 60	3.00
	Sorbitan stearate	2.00
	Cetyl alcohol	0.75
	Paraffinum	3.00
	Isopropyl myristate	2.50
	Caprylic-caproic triglycerides	2.00
	Dimethicone	0.50
	Propylene glycol	3.00
	Aqua	100	c.s.p.

This formulation is applied in body oil.

This formulation is completed with 0.20 g of LAE, and the preservative capacity is evaluated and it is compared with the formulation without LAE. The results are shown in the Table 10.

TABLE 10
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	1.5 · 106	4.5 · 106
		Fungi	2.6 · 104	7.6 · 104
		Yeast	3.2 · 104	7.2 · 104
	7 days	Aerobes	4.5 · 106	7.6 · 103
		Fungi	7.7 · 103	1.4 · 102
		Yeast	8.4 · 103	2.3 · 102
	14 days	Aerobes	6.3 · 106	<9.9 · 101
		Fungi	1.6 · 104	<9.9 · 101
		Yeast	7.9 · 103	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 10

The composition of a toothpaste formulation is (in g):

	Calcium carbonate	16.00
	Dicalcium phosphate	24.00
	Silica	2.00
	Petrolatum	10.00
	Glycerine	20.00
	Sodium fluoride	0.20
	Hydroxyethyl cellulose	1.00
	Lauroyl sarcosine	2.00
	Aqua	100	c.s.p.

This formulation is completed with 0.20 g of LAE, and the preservative capacity is evaluated and it is compared with the formulation without LAE. The results are shown in the Table 11.

TABLE 11
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	6.5 · 106	4.5 · 106
		Fungi	9.6 · 104	5.6 · 104
		Yeast	4.8 · 104	4.2 · 104
	7 days	Aerobes	3.5 · 107	3.3 · 103
		Fungi	1.6 · 104	1.6 · 102
		Yeast	5.2 · 103	1.2 · 102
	14 days	Aerobes	6.5 · 107	8.0 · 102
		Fungi	1.7 · 104	<9.9 · 101
		Yeast	4.8 · 103	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 11

The composition of a formulation to obtain an aqueous solution with surfactants, is (in g):

	Sodium lauryl sulfate (sol. 27%)	12.00
	Cocamidopropyl betaine	5.00
	Disodium cocoamfoacetate	5.00
	Polyquaternium11	1.00
	Lactic acid	0.25
	Sodium chloride	0.50
	Aqua	100	c.s.p.

This formulation is applied in shampoos cosmetic formulations.

This formulation is completed with 0.20 g of LAE, and the preservative capacity is evaluated and it is compared with the formulation without LAE. The results are shown in the Table 12.

TABLE 12
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	3.7 · 106	3.3 · 106
		Fungi	7.6 · 104	9.6 · 104
		Yeast	3.2 · 104	4.2 · 104
	7 days	Aerobes	5.9 · 106	4.8 · 103
		Fungi	9.6 · 102	1.1 · 102
		Yeast	4.9 · 103	1.2 · 102
	14 days	Aerobes	6.3 · 106	7.0 · 102
		Fungi	1.1 · 103	<9.9 · 101
		Yeast	5.2 · 103	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 12

The composition of a formulation to obtain an oil-in-water emulsion with non-ionic surfactants, is (in g):

	Glyceryl stearate + PEG 100 stearate	4.00
	Cetyl alcohol + sodium cetyl sulfate	2.00
	Caprylic-caproic triglycerides	4.00
	Isopropyl mirystate	2.50
	Paraffinum	2.00
	Dimethicone	0.50
	Glycerin	3.00
	Wheat (triticum vulgare) germ protein	2.00
	Aqua	100	c.s.p.

This formulation is applied in a face cream for skin care.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the Table 13.

TABLE 13
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	3.3 · 106	1.1 · 106
		Fungi	1.6 · 104	1.7 · 104
		Yeast	2.2 · 104	3.2 · 104
	7 days	Aerobes	4.3 · 106	3.7 · 104
		Fungi	1.9 · 102	8.7 · 102
		Yeast	2.5 · 102	9.2 · 102
	14 days	Aerobes	4.3 · 106	1.9 · 103
		Fungi	1.8 · 102	<9.9 · 101
		Yeast	2.9 · 102	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 13

The composition of a formulation to obtain an oil-in-water emulsion with non-ionic surfactants, is (in g):

	Polysorbate 60	3.00
	Sorbitan stearate	2.00
	Cetyl alcohol	2.50
	Paraffinum	2.00
	Caprylic-caproic triglycerides	2.00
	Ethyl hexyl methoxycinnamate	5.00
	Benzophenone 3	1.00
	Dimethicone	0.50
	Propylene glycol	3.00
	Aqua	100	c.s.p.

This formulation is applied in a sun protector cosmetic formulator.

This formulation is completed with 0.20 g of LAE and its capacity of preservation is evaluated against the formulation without LAE. The results are shown in the Table 14.

TABLE 14
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	4.4 · 106	3.1 · 106
		Fungi	5.7 · 104	4.9 · 104
		Yeast	2.7 · 104	3.8 · 104
	7 days	Aerobes	6.3 · 106	8.4 · 103
		Fungi	5.1 · 102	2.7 · 102
		Yeast	2.3 · 102	4.2 · 102
	14 days	Aerobes	7.2 · 106	7.5 · 102
		Fungi	5.9 · 102	<9.9 · 101
		Yeast	2.8 · 102	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 14

The composition of a formulation to obtain an oil-in-water emulsion with non-ionic surfactants is (in g):

	Cetyl Dimethicone copolyol	3.00
	Isohexadecane	4.00
	Paraffinum	5.00
	Isopropyl myristate	3.00
	Caprylic-caproic triglycerides	3.00
	Ethyl hexyl methoxycinnamate	5.00
	Benzophenone 3	1.00
	Glycerin	3.00
	Sodium chloride	0.50
	Aqua	100	c.s.p.

This formulation is applied in a sun protector cosmetic product.

This formulation is completed with 0.20 g of LAE, and the preservative capacity is evaluated and it is compared with the formulation without LAE. The results are shown in the Table 15.

TABLE 15
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	2.8 · 106	1.4 · 106
		Fungi	5.5 · 104	5.3 · 104
		Yeast	7.7 · 104	7.9 · 104
	7 days	Aerobes	4.4 · 106	9.4 · 102
		Fungi	8.6 · 102	6.7 · 102
		Yeast	8.3 · 102	4.5 · 102
	14 days	Aerobes	7.2 · 106	8.7 · 102
		Fungi	5.8 · 102	<9.9 · 101
		Yeast	7.9 · 102	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.

Example 15

The composition of a formulation to obtain an emulsion for hands care, is (in g):

	Cetyl alcohol + ceteareth 20	6.00
	Isopropyl myristate	2.00
	Caprylic-caproic triglycerides	1.00
	Dimethicone	1.00
	Benzophenone 3	1.00
	Glycerin	6.00
	Carbomer 940	0.10
	Triethanolamine	0.10
	Aqua	100	c.s.p.

This formulation is completed with 0.20 g of LAE, and the preservative capacity is evaluated and it is compared with the formulation without LAE. The results are shown in the Table 16.

TABLE 16
			Without LAE	With LAE
		Microorganism	(cfu/mL)	(cfu/mL)
	Initial	Aerobes	4.5 · 106	4.4 · 106
		Fungi	6.1 · 104	5.8 · 104
		Yeast	8.8 · 104	8.6 · 104
	7 days	Aerobes	7.4 · 106	3.3 · 103
		Fungi	7.8 · 102	8.7 · 102
		Yeast	8.9 · 102	7.2 · 102
	14 days	Aerobes	4.4 · 106	<9.9 · 101
		Fungi	9.8 · 102	<9.9 · 101
		Yeast	1.2 · 103	<9.9 · 101

At 28 days no increase has been detected from the 14 days' count.