Drug – bio-affecting and body treating compositions – Live hair or scalp treating compositions – Polymer containing
Reexamination Certificate
1998-02-27
2001-02-06
Raymond, Richard L. (Department: 1624)
Drug, bio-affecting and body treating compositions
Live hair or scalp treating compositions
Polymer containing
C424S401000
Reexamination Certificate
active
06183732
ABSTRACT:
The present invention relates to a chemical composition, particularly although not exclusively, a chemical composition intended for personal washing.
The human skin comprises three physiologically different layers. The outermost layer is called the Epidermis and itself comprises an outer layer known as the Stratum Corneum made up of dead keratinised flattened cells and an inner layer known as the Basal layer which comprises cells that divide and migrate upwards to produce the Stratum Corneum.
The Epidermis thus comprises a dead avascular layer of stratified squamous epithelium. It gives important protection to the human body from assault by microbes, bacteria and fungi.
The Stratum Comeum forms the barrier between the internal body and the external environment and is responsible for maintaining normal water loss from the body to balance the water supply and the evaporation rate. The water content of the Stratum Comeum is an equilibrium between moisture gain and moisture loss. Moisture is gained in the skin as the cells divide and by the external addition to the skin of a cream, lotion or the like. Moisture is lost from the skin as it naturally dries out due to the external environment. Thus for the skin to gain moisture there must be a rise in the water content of the Stratum Comeum.
In order to reduce the amount of water lost to the external environment a traditional practice comprises applying a residual film of a composition including an occlusive agent or humectant to the skin's surface. An occlusive agent leaves a residual film which is a mechanical barrier preventing water from evaporating from the Stratum Corneum and from passing from the external environment through to the skin. A humectant however is a hygroscopic material which acts like a sponge, holding water close to the skin and permitting a higher level of water to be maintained in the Stratum Corneum.
Many humectants have been proposed in the past in a wide variety of skin care products. For example, WO 94/17783 (Unilever N.V.et al) describes a cleansing composition intended for use as a personal washing product, such as facial wash foams, bath foams and hair shampoos, in which the composition includes as a surfactant acyl glycolate and a cosurfactant, and optionally includes a humectant such as glycerine and a foam modifying agent such as cationic polymers for example polyquatemium-24 or polyquaternium-10.
It is an object of the present invention to provide a composition comprising a mixture of humectants having improved properties on application to human skin.
It is a further object of the present invention to provide a composition comprising a mixture of humectants and a surfactant for use in washing human skin.
It is a further object of the present invention to provide a composition in the form of a shower gel comprising a surfactant and a mixture of humectants, wherein the shower gel provides improved moisturising and skin feel effects.
According to the present invention, there is provided a composition for use in a topical skin formulation comprising:
(i) polyalcohol humectant;
(ii) a mixture of at least two polyquaternary compounds, one of which is a cationic copolymer and one of which is an amphoteric copolymer, the copolymers being present in a weight ratio of cationic copolymer to amphoteric copolymer of 1:1.75 to 1:6;
wherein the weight ratio of polyalcohol humectant to said mixture lies in the range 1:0.06 to 1:0.1.
The polyalcohol humectant is preferably selected from the group comprising glycerol, propylene glycol, butylene glycol and mixtures thereof. The polyalcohol humectant is suitably glycerol which has good moisturising properties with respect to the human skin.
When employed, however, as part for example of a shower gel the polyalcohol humectant which is water soluble can rapidly get removed when rinsing the skin. In order to increase the substantivity of for example the glycerol the cationic copolymer, which also acts as a moisturising agent, is suitably Polyquatemium-7 which is a copolymer of dimethyl diallyl ammonium chloride and acryl amide.
The amphoteric copolymer is suitably Polyquatemium-39 which is a 1:2:1 by weight terpolymer of acrylic acid, dimethyl diallyl ammonium chloride and acryl amide.
The amphoteric polymer contributes to the skin feel of the composition and its ease of application. The presence of the amphoteric polymer may potentially effect the ability of the cationic copolymer to increase the substantivity of the glycerol. By means of the present invention, however, the combination of at least the present three ingredients can provide a synergistic moisturising effect greater than the sum of the effect of each taken separately.
Preferably the weight ratio of cationic copolymer to amphoteric copolymer lies in the range 1:1.75 to 1:3. Ideally it is 1:2.
Suitably the composition contains a surfactant. The surfactant can be any surfactant or mixture of surfactants suitable for use in personal cleansing products. Suitably the surfactant is an anionic surfactant. Preferably the surfactant is sodium laureth sulphate.
Quaternised polymers are high molecular weight, water soluble polymers having cationic or amphoteric properties. Different polymers can have different levels of quaternisation. Quaternised polymers such as Polyquaternium 7 and Polyquatemium-39 are available commercially from a number of suppliers. They are available for example in the form of 10 wt % aqueous solutions from Chemviron Speciality Chemicals under their trade name “Merquat”.
Particular examples suitable for use in the present invention include “Merquat S” which is 10 % aqueous solution of a highly charged cationic copolymer of dimethyl diallyl ammonium chloride and acryl amide having a molecular weight of 7×10
6
and a viscosity of 9000 to 15000 cps at 25° C. measured on a Brookfield RVF#4 spindle at 10 RPM, and “Merquat Plus 3330” which is 10 wt % aqueous solution of a polyampholyte terpolymer consisting of acrylic acid, dimethyl diallyl ammonium chloride and acryl amide in a 25:50:25 weight ratio of acrylic acid:DMDAAC:acryl amide, the terpolymer having a molecular weight of 4×10
6
and the solution having a viscosity of 4,400 to 10,400 cps at 25° C. measured using a Brookfield:LVF #4 spindle at 30 RPM.
Suitably the present composition comprises a composition comprising 10 to 20 wt % anionic surfactant, 1.5 to 6.0 wt % polyalcohol humectant, 0.225 to 0.425 wt % mixture of polyquaternary compounds and water. Preferably the cationic copolymer is present at a level between 0.025 wt % and 0.125 wt % and the amphoteric copolymer is present at a level between 0.175 wt % and 0.30 wt %.
Even more suitably the present composition comprises:
15 wt % sodium laureth sulphate
4 wt % glycerol
0.2 wt % of a 1:2:1 terpolymer of acrylic acid, dimethyl diallyl ammonium chloride and acryl amide
0.1 wt % of a copolymer of dimethyl diallyl ammonium chloride and acryl amide and water to 100%.
The weight per cent amounts of polyquaternary compounds recited are the absolute amounts present in the composition; not the quantity to be added in for example the form of aqueous solution supplied by the manufacturers.
Preferably the present composition is in the form of a shower gel or bath gel. Other forms are however not excluded and include bars, creams, lotions, sun care products, shaving creams, conditioners and the like. Minor ingredients can be included such as perfume, colour, pearlescer, thickener, pH modifier, sun block, preservative, etc.
The present compositions can be prepared by admixing the ingredients together.
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patent:
Johnson & Johnson Consumer Companies
Liu Hong
Mangini Michele G.
Raymond Richard L.
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