Bath additive composition containing polyglycerol fatty acid ester mixture

A bath additive composition, in particular an oil bath preparation, containing at least one surface-active component, preferably a water-soluble emulsifier, at least one oily or oil-containing component selected from the natural and synthetic, mineral, ethereal and fatty animal and vegetable oils, optionally a solvent or solvent mixture and also further auxiliaries and additives, the bath additive preparation containing 10 to 60 wt-% of a polyglycerol fatty acid ester mixture as the water-soluble emulsifier and/or solubilizer, 10 to 60 wt-% of an oil, oil mixture and/or oil component having cosmetic and/or therapeutic activity and 0 to 70 wt-% of water, the polyglycerol fatty acid ester mixture containing 0 to 5 parts by weight diglycerol fatty acid esters, 20 to 65 parts by weight triglycerol fatty acid esters, 20 to 50 parts by weight tetraglycerol fatty acid esters, and 5 to 40 parts by weight higher polyglycerol fatty acid esters, for a total of 100 parts by weight, and the fatty acid component consisting of one or more fatty acids selected from the saturated and/or unsaturated, branched and/or unbranched C.sub.6 - to C.sub.14 - fatty acids containing less than 10 wt-% fatty acids having more than 14 carbon atoms.

BACKGROUND OF THE INVENTION 
The present invention relates to a bath additive composition, in particular 
an oil bath preparation, containing at least one surface-active component, 
preferably a water-soluble emulsifier, at least one oily or oil-containing 
component selected from the natural and synthetic, mineral, ethereal and 
fatty animal and vegetable oils, optionally a solvent or solvent mixture, 
and optionally further additives and/or adjuvants. 
Baths containing added bath preparations having a suitable cosmetic, 
therapeutic and/or physiological effect (bath additive preparations) are 
enjoying increasing popularity, since they not only serve to clean the 
body, but also have a regenerating and normalizing effect on the skin due 
to their content of skin care ingredients, and have a refreshing, relaxing 
and possibly healing effect on the human body due to their content of 
medicinal or therapeutic additives, such as, for example, ethereal oils. 
Bath preparations of this type are also called oil or skin-care baths. 
Moreover, they can also contain perfuming additives. 
Bath preparations of this type are supplied in solid, liquid (including 
gelatinous and highly viscous) or pasty form. Liquid preparations are 
preferably used which frequently take the form of aqueous or oily 
emulsions or dispersions. They customarily contain the following primary 
constituents: at least one surface-active compound which acts as a 
surfactant, emulsifying, dispersing, solubilizing and/or wetting agent and 
is either largely water-soluble or largely fat-soluble; at least one 
active compound which exerts a caring, protecting, regenerating, 
vitalizing and/or medicinal therapeutic effect, and optionally an aqueous 
or organic solvent or solvent mixture. 
Pure cosmetic active ingredients include, for example, additives based on 
lipids and other creaming, oil-restoring substances which affect the 
water-binding power of the skin. These also include certain vegetable and 
animal oils which have cosmetic properties. A medicinal therapeutic effect 
on the human body can be achieved, for example, by means of specific 
ethereal oils or vegetable extracts. 
As further constituents, bath additive preparations can contain foam 
improvers and enhancers, pH regulators, preservatives having antiseptic, 
bactericidal or bacteriostatic properties, antioxidants, thickeners or 
viscosity regulators, colorants and/or fragrances. 
The bath preparations are added to the bath water in accordance with 
appropriate dosage instructions, the preparation being adjusted to assure 
a uniform distribution of the constituents of the formulation in the bath 
water or spreading of the preparation on the surface of the water. 
Bath preparations in accordance with the prior art are disadvantageous in 
two different respects. 
On the one hand, it is difficult to incorporate oily and oil-containing 
additives, especially natural or identical-to-natural ethereal or fatty 
vegetable oils, in cosmetic and pharmaceutical preparations since it is 
difficult to emulsify substances of this type. Therefore, it is necessary 
to use special emulsifiers or emulsifier mixtures. In the prior art, these 
were primarily ethylene oxide addition compounds which, although they have 
good emulsifying properties, are less desirable because of their 
toxicological and dermatological properties, and in particular cannot 
exert cosmetic effects. 
On the other hand, known bath preparations which are intended to have both 
a cosmetic and a medicinal or therapeutic utility, usually have a 
complicated and expensive recipe. 
In addition, emulsifiers which are suitable not only for preparing stable 
oil/water systems, such as, for example, bath oil formulations, but which 
also exert a physiological action, in particular a skin-caring and/or 
skin-protecting effect, have not been available in sufficient amounts. 
SUMMARY OF THE INVENTION 
It is the object of the present invention to provide an improved bath 
additive preparation. 
Another object of the invention is to provide a bath additive composition 
which is particularly suitable as an oil bath preparation. 
A further object of the invention is to provide a cosmetic bath additive 
composition which exerts skin-care, skin-protecting and/or a 
skin-regenerating action on the human skin. 
It is also an object of the invention to provide a bath additive 
composition which exerts a therapeutic effect on the human body. 
An additional object of the invention is to provide a bath additive 
composition which has a simple recipe in which a water-soluble, liquid 
emulsifier is used. 
Yet another object of the invention is to provide a bath additive 
composition which is non-toxic and dermatologically acceptable. 
These and other objects of the invention are achieved in accordance with 
the present invention by providing a bath additive composition comprising 
10 to 60 wt-% of at least one water-soluble surface-active component, 10 
to 60 wt-% of at least one oily or oil-containing component having 
cosmetic or therapeutic activity selected from the group consisting of 
natural and synthetic, mineral, ethereal and fatty animal and vegetable 
oils, and 0 to 70 wt-% water, wherein the at least one surface-active 
component is a polyglycerol fatty acid ester mixture consisting of 0 to 5 
parts by weight diglycerol fatty acid esters, 20 to 65 parts by weight 
triglycerol fatty acid esters, 20 to 50 parts by weight tetraglycerol 
fatty acid esters, and 5 to 40 parts by weight higher polyglycerol fatty 
acid esters, for a total of 100 parts by weight, in which the fatty acid 
consists of at least one fatty acid selected from the group consisting of 
saturated and unsaturated, branched and unbranched C.sub.6 - to C.sub.14 - 
fatty acids containing less than 10 wt-% of fatty acids having more than 
14 carbon atoms. 
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
The bath preparation according to the invention contains at least one 
polyglycerol fatty acid ester as a surface-active constituent. Compounds 
of this type or mixtures of polyglycerol fatty acid esters are known as 
solubilizers and emulsifiers or dispersing agents in cosmetic and 
pharmaceutical preparations and in foodstuffs. Until now, however, no 
polyglycerol fatty acid ester mixture has been available which exists as a 
liquid, water-soluble product and has an HLB of over 8, so that is 
suitable for the preparation of stable oil/water systems, in particular 
for emulsifying ethereal and fatty vegetable or animal oils in bath 
preparations, and which has a narrow distribution with respect to the 
glycerol oligomers employed. 
Surprisingly, it has now been found that a bath additive preparation 
according to the present invention, in particular an oil bath preparation, 
fulfills all of the objects set forth above. The bath additive composition 
in accordance with the present invention is characterized in that it 
comprises: 
10 to 60 wt-% of.fwdarw.a polyglycerol fatty acid ester mixture as a 
water-soluble emulsifier and/or solubilizer; 
10 to 60 wt-% of.fwdarw.an oil, oil mixture and/or oil component which has 
a cosmetic and/or therapeutic effect; and 
0 to 70 wt-% of.fwdarw.water, 
said polyglycerol fatty acid ester mixture consisting of: 
0 to 5 parts by weight diglycerol fatty acid esters, 
20 to 65 parts by weight triglycerol fatty acid esters, 
20 to 50 parts by weight tetraglycerol fatty acid esters, and 
5 to 40 parts by weight higher polyglycerol fatty acid esters, for a total 
of 100 parts by weight, and said fatty acid ester mixture containing as 
the fatty acid component thereof at least one fatty acid selected from the 
group consisting of C.sub.6 - to C.sub.14 - fatty acids containing less 
than 10 wt-% fatty acid having more than 14 carbon atoms. The fatty acid 
component may be saturated and/or unsaturated and branched and/or 
unbranched. 
In particular, the polyglycerol fatty acid ester mixture employed used in 
accordance with the invention takes on a double function. On the one hand 
it has an HLB of above 8 and is outstandingly suitable for emulsifying and 
solubilizing oily and oil-containing substances, particularly ethereal and 
fatty vegetable oils, so that it is possible to establish phase equilibria 
which completely satisfy all usual criteria with respect to stability. 
The outstanding emulsifying action of the polyglycerol fatty acid ester 
mixture according to the invention is also retained when the bath additive 
preparation according to the invention is incorporated in highly dilute 
aqueous solutions, such as, for example, bath water, whereby it 
surprisingly has been found that spontaneous emulsification of the oily or 
oil-containing component takes place. 
On the other hand, the polyglycerol fatty acid ester mixture according to 
the invention is not only physiologically acceptable and readily 
biodegradable, but it also has a skin-caring and skin-protecting action, 
particularly an oil-restoring effect, which gives the skin a pleasant 
feeling after the bath even when the bath additive preparation according 
to the invention has been highly diluted in the bath water, and 
counteracts the tendency of the bath water to dry out the skin. 
Because of this double function of the polyglycerol fatty acid ester 
mixture according to the invention, the bath additive preparation of the 
invention has a cosmetic action with respect to protection and care of the 
skin as a result of the presence of just the polyglycerol fatty acid ester 
mixture alone, and the addition of a further oil, oil mixture and/or oil 
component which has a cosmetic effect and/or therapeutic effect gives, 
depending on the oil, oil mixture or oil component employed, an increased 
cosmetic effect and/or has a healing, relieving, tranquilizing and/or 
vitalizing physiological effect. 
Even if the composition consists of only two constituents, namely the 
emulsifier employed in accordance with the invention and an oil or oil 
mixture having a therapeutic effect, it is possible to provide an oil bath 
formulation using the bath additive preparation according to the invention 
which has a cosmetic and a medicinal therapeutic effect and additionally 
causes spontaneous emulsification of the oil in the bath water. 
In a bath prepared using the bath additive preparation according to the 
invention, the constituents of the oil bath formulation are finely 
dispersed in the bath water and/or on the water surface (spreading) and 
can therefore optimally achieve their intended effect. The phase 
equilibria established by the polyglycerol fatty acid ester mixture 
according to the invention are not disturbed either by the usual strongly 
varying temperature conditions in the bath water or by electrolytes, in 
particular inorganic salts, dissolved in the water. 
The bath additive preparation according to the invention also constitutes 
an ecologically advantageous oil bath formulation since residues of the 
bath additive preparation contained in the used bath water are readily 
biodegradable, and the emulsifier employed according to the invention is 
also completely physiologically acceptable. 
In accordance with a preferred embodiment, the bath additive preparation of 
the invention contains 
15 to 50 wt-% of a polyglycerol fatty acid ester mixture, 
15 to 50 wt-% of an oil, oil mixture and/or oil component which has a 
cosmetic and/or therapeutic effect, and 
0.5 to 60 wt-% of water; 
wherein the polyglycerol fatty acid ester mixture contains: 
0 to 3 parts by weight diglycerol fatty acid esters, 
22 to 32 parts by weight triglycerol fatty acid esters, 
39 to 49 parts by weight tetraglycerol fatty acid esters, and 
24 to 34 parts by weight higher polyglycerol fatty acid esters; and 
the fatty acid component consists of one or more fatty acids selected from 
the group consisting of saturated and unsaturated, branched and unbranched 
C.sub.8 - to C.sub.12 -fatty acids containing less than 5 wt-% of fatty 
acids having more than 14 carbon atoms. 
Bath additive preparations according to the invention preferably contain 
caprylic acid, capric acid, lauric acid, undecenoic acid, 2-ethylhexanoic 
acid or coconut fatty acid as the fatty acid component in the polyglycerol 
fatty acid ester mixture according to the invention. It is also possible 
in accordance with the invention for the foregoing fatty acids to be 
present as mixtures with one another. Additional or particular properties 
can be provided in the polyglycerol fatty acid ester mixture according to 
the invention by means of the aforementioned fatty acid compounds. These 
include, for example, either particular skin-care properties or, as in the 
case of undecenoic acid, an antimycotic action, which is advantageous for 
preservation of the bath additive preparation. 
In accordance with a further preferred embodiment, the bath additive 
composition according to the invention contain at least one fatty 
vegetable oil, preferably jojoba oil, soya oil, sesame oil, groundnut oil, 
sunflower oil, olive oil, palm oil, palm kernel oil, castor oil, cocoa 
oil, coconut oil, almond oil or wheatgerm oil, as the oil having a 
cosmetic effect, these oils being employed either individually or in 
mixtures with one another. 
In addition, the bath additive preparation according to the invention may 
contain animal oils as the oil having cosmetic activity. For example, one 
preferred animal oil is synthetic uropygial gland oil, which has the 
effect of rendering the skin hydrophobic. 
Using these natural or identical-to-natural oils or oil mixtures, the bath 
additive compositions according to the invention are provided with 
skin-caring, skin-protecting and/or skin-regenerating effects which 
supplement the cosmetic properties, particularly the oil-restoring 
properties, of the polyglycerol fatty acid ester mixture according to the 
invention. 
Particular pharmacological or medicinal therapeutic properties are provided 
in the bath additive preparation according to the invention by the use of 
oils or oil mixtures which have an appropriate activity, preferably by 
addition of ethereal oils, such as rosemary oil, lavender oil, balm mint 
oil, sage oil, garlic oil, juniper berry oil, aniseed oil, cardamon oil, 
pimento oil, aniseed oil, caraway oil, lemon oil, orange oil, peppermint 
oil, camphor oil, pine-needle oil or eucalyptus oil, these oils being 
employed either individually or in mixtures with one another. These oils 
impart a medicinal activity to the bath additive composition according to 
the invention in that they exert a relieving or healing action on the 
human body and/or exhibit their therapeutic activity by means of a 
relaxing, refreshing or vitalizing effect. 
According to a further preferred embodiment, the bath additive preparation 
according to the invention contains natural or synthetic compounds, such 
as isopropyl myristate, isopropyl palmirate, decyl oleate, cetyl stearyl 
isononanoate, 2-octyldodecanol, lanolin or cholesterol derivatives or 
caprylic/capric acid triglyceride as the oil and/or oil component having a 
cosmetic effect, these compounds being employed either individually or in 
mixtures with one another and also having a skin-caring and/or 
oil-restoring action. 
The aforementioned natural or synthetic, fatty vegetable and animal oils 
and also ethereal oils and oil components can be used as complete or 
partial replacements for each other in the bath additive preparation 
according to the invention. They may also be completely or partially 
replaced in the bath additive preparation according to the invention by 
mineral oils or oil mixtures which have a pharmaceutical or therapeutic 
effect, such as, for example, liquid paraffin. 
An additional perfuming effect can be provided in the bath additive 
preparation according to the invention by the addition of certain ethereal 
oils, preferably rose oil, jasmine oil, violet oil, mimosa oil, orange 
oil, neroli oil, patchouli oil, sandalwood oil or cinnamon oil and also by 
addition of synthetic or natural perfume compositions, these oils or 
perfume compositions being employed either individually or in mixtures 
with one another. In this way a so-called scented bath is obtained. 
Solutions of vegetable extracts, such as those of camomile, can be 
contained in the bath additive preparation as further therapeutically 
active substances in order, for example, to relieve or to heal 
inflammation of the skin and/or in the respiratory tract organs. 
The bath additive preparation according to the invention can also be 
formulated as a foam bath. To achieve this, foaming agents are 
additionally incorporated, such as, for example, anionic surfactants, 
preferably alkyl ether sulfonates and sulfates, in particular sodium 
lauryl ether sulfate, in order to obtain a good foaming power even in the 
presence of substantial amounts of fats or oils. 
As the solvent, the bath additive preparation according to the invention 
can preferably contain demineralized water which optionally contains small 
amounts of water-soluble organic solvents which are acceptable in health 
terms. Such organic solvents include, for example, glycerol and/or lower 
alcohols, such as 1,2-propanediol, which can be employed as additional 
solubilizers and prevent turbidity due to flocculation of organic 
constituents in the bath additive preparation. 
It is particularly advantageous to use small amounts of water as a solvent 
if the bath additive preparation of emulsifying or solubilizing 
polyglycerol fatty acid ester mixture according to the invention and the 
oily or oil-containing component forms a turbid solution. An optically 
clear solution is then obtained by the addition of water. 
The polyglycerol fatty acid ester mixture according to the invention 
exhibits its superiority compared with conventional, commercially 
available products particularly with respect to its excellent solubilizing 
power in water-containing oil bath preparations. 
The polyglycerol fatty acid ester mixture according to the invention may 
additionally be combined with a further polyglycerol fatty acid ester 
mixture as a solubilizer. To do this, a polyglycerol caprate or a 
polyglycerol cocoate, preferably prepared according to our co-pending U.S. 
patent application Ser. No. 07/838,330, now U.S. Pat. No. 5,247,114 the 
entire disclosure of which is incorporated herein by reference, is 
particularly suitable. 
When the vegetable oil content is high, particularly in a water-containing 
preparation, it may be advantageous to protect the bath additive 
preparation according to the invention against microbial decay. Compounds 
such as benzoates, benzoic acid derivatives, sorbates, microbiologically 
active phenols, such as 2,6-di-tert-butyl-4-methylphenol, and dioxanes, 
such as 5-bromo-5-nitro-1,3dioxane, can be employed as bacteriostatic or 
bactericidal preservatives. 
To protect the bath additive preparation according to the invention against 
oxidative decomposition, antioxidants, such as tocopherols, in particular 
vitamin E, and/or butyl-hydroxytoluene, can be included in the 
composition. These preservatives are employed in the bath additive 
preparation according to the invention in customary amounts. 
Further additives or adjuvants contained in the bath additive compositions 
according to the invention may include pH regulators, thickeners or 
viscosity regulating agents, such as polyglycols, propylene glycol, 
ethanol, isopropanol, and/or inorganic salts, preferably sodium chloride, 
complexing agents for masking metal ions and coloring agents. 
The pH of the bath additive preparation is preferably between 5.5 and 7.5, 
depending on the water content. 
The bath additive preparation according to the invention displays its 
advantageous action in particular in an amount of from 15 to 30 ml in 
about 200 liters of bath water. 
The bath additive composition according to the invention is prepared by 
simply mixing the constituents in appropriate mixing devices; the sequence 
of addition of the individual components is not critical. 
The polyglycerol fatty acid ester mixture according to the invention is 
obtained by a modification of the process disclosed in our co-pending U.S. 
patent application Ser. No. 08/089820, filed Jul. 12, 1993, (Attorney 
Docket No. 173/41298; claiming priority of Federal Republic of Germany 
application no. P 42 23 407.7), the disclosure of which is incorporated 
herein by reference. The process is modified by esterifying a polyglycerol 
containing per 100 parts by weight: 
0 to 5 parts by weight diglycerol, 
20 to 65 parts by weight triglycerol, 
20 to 50 parts by weight tetraglycerol, and 
5 to 40 parts by weight higher polyglycerols, 
with one or more fatty acids selected from the saturated and/or 
unsaturated, branched and/or unbranched C.sub.6 - to C.sub.14 -fatty 
acids, the fatty acid or the fatty acid mixture having a content of less 
than 10 wt-% of fatty acids having more than 14 carbon atoms, in a molar 
ratio of the polyglycerol to the fatty acid or to the fatty acid mixture 
of 4:1 to 1:1 in accordance with said U.S. patent application Ser. No. 
08/089820 and optionally working up the resulting polyglycerol fatty acid 
ester mixture. 
Preferably, a polyglycerol which contains per 100 parts by weight: 
0 to 3 parts by weight diglycerol, 
22 to 32 parts by weight triglycerol, 
39 to 49 parts by weight tetraglycerol, and 
24 to 34 parts by weight higher polyglycerols is esterified with one or 
more fatty acids selected from the saturated and/or unsaturated, branched 
and/or unbranched C.sub.8 -to C.sub.12 - fatty acids, the fatty acid or 
the fatty acid mixture containing less than 5 wt-% of fatty acids having 
more than 14 carbon atoms, in a molar ratio of the polyglycerol to fatty 
acid or fatty acid mixture of from 2.5:1 to 1.5:1, preferably 2:1, in 
accordance with said U.S. patent application Ser. No. 08/089820, and 
optionally working up the resulting polyglycerol fatty acid ester mixture.