FIELD OF THE INVENTION
The present invention relates to stabilized skin care compositions with colored and colorless active ingredients. More particularly the invention relates to the composition comprising a high interfacial phase emulsification system (HIP) acting as a complexing agent comprising Cyclopentasiloxane, Dimethicone, crosspolymer of Dimethicone Laureth-23 and Laureth -4 and β carotene, lycopene and other uncolored, unstable actives at low concentration.

BACKGROUND AND PRIOR ART OF THE INVENTION
Michael Starch et al, Expanding Silicone Technologies for Sun Care: Performance Complements Aesthetics provides the use of silicone compounds, such as cyclopentasiloxane and dimethicone crosspolymer, in skin care products for improving in vivo SPF of the skin care production.
Silicone Elastomer Blends for Delivery of Actives in Personal Care Formulations IPCOM000133201D, Jan 18, 2006 UTC available on http://priorartdatabase.com, revealed that Dow Corning® 9040 Silicone Elastomer Blend with the INCI name: Cyclomethicone (and) Dimethicone Crosspolymer, which contains silicone elastomer swollen with decamethylcyclopentasiloxane (commonly abbreviated as “D5”) exhibits excellent sensory feel and is useful as a rheology modifier for various types of personal care formulations where it can improve stability, suspend active ingredients (such as sunscreen oils, natural lipids, and oil-soluble vitamins and vitamin derivatives.), and modify the aesthetics (skin feel) of the formula.
Drager et al; New Emulsion Technology Makes Formulation Easy by Michael Starch Dow Corning Corporation; Dow Dispersion Sciences describes the use of a novel process technology to prepare high internal phase (HIP) emulsions, which can provide solutions to a number of formulating issues. HIP emulsions have been used as a basis for pre-emulsified concentrates of emollients, moisturizers and sunscreens. The small particle size and size-distribution control provided by the new technology allow formulators to create skin care products with distinctive aesthetics. The emulsion concentrates allow simple cold mixing and, because of their excellent stability, formulators can easily adjust emollient levels to obtain the desired skin feel. The result can be greater speed in formulation and scale-up of new skin care products.
US 2007/0224295 disclose the use of cyclopentasiloxane, dimethicone, cross polymer of dimethicone in skin care formulations.
US 6194452 relates to a stable pharmaceutical composition comprising: a silicone component of a solution (5 to 90% by weight) of a combination of at least one linear silicone compound and at least one cyclopolysiloxane as the sole silicone component of the composition; and a source of pharmaceutically acceptable ascorbic acid dispersed in the silicone component, wherein the solution is present in an amount sufficient to inhibit degradation of the ascorbic acid. The linear silicone compound comprises dimethicone and the cyclopolysiloxane compound comprises cyclomethicone, cyclopentasiloxane, or both. The composition may further comprise vitamin B12, carotenoids such as -carotene.
US 7592024 provide delivery of an anti-aging extract in a cosmetically acceptable vehicle which comprises of a water-in-oil or oil-in-water emulsion. the water-in-silicone emulsifiers like, dimethicone PEG 10/15 crosspolymer, dimethicone copolyol, cetyl dimethicone copolyol, PEG-15 lauryl dimethicone crosspolymer, laurylmethicone crosspolymer, cyclomethicone and dimethicone copolyol, dimethicone copolyol (and) caprylic/capric triglycerides, polyglyceryl-4 isostearate (and) cetyl dimethicone copolyol (and) hexyl laurate, and dimethicone copolyol (and) cyclopentasiloxane. The document further provides inclusion of other actives like antioxidant such as ascorbic acid and its derivatives/esters; alpha-hydroxyacids; beta-carotene; catechins; lycopene.
Robert et al; Recent trends in skin care polymers: new polymers and polymeric systems continue to drive skin care innovation;, Household and Personal Products Industry, Apr 1, 2006 provides the application of polymers and polymeric systems in skin care cosmetics. The document teaches that the polymers with specific side groups may provide the basis for a new class of antimicrobial agents and sunscreens that can be delivered effectively from aqueous solution. The document also provides a general view of the applications of various silicone resins to the skin such as dimethicone and trimethylsiloxysilicate, DC 593 Fluid from Dow Coming or KF-7312 from Shin Etsu; and a low oil-absorbing spherical powder, including Rubinate polyurethane powder from Huntsman of Belgium; DC 9506 powder from Dow Coming; BPA polymethylmethacrylate and MSS-500N silica both from Kobo Products. Silicone emulsions confer good feel on skin, but they usually require special emulsifiers such as dimethicone copolyol. Non-aqueous emulsions of silicones are useful delivery systems for cosmetic applications, particularly when the presence of water initiates a process that changes the nature of the cosmetic composition.
US 6,793,929 provides w/o emulsion comprising at least one interface-active substance as alkylmethicone copolyols and/or alkyldimethicone copolyols, and one or more cationic polymers. The interface-active substances in the finished cosmetic preparations range from 0.1-30% by total weight of preparation. The document teaches preparation of stable, flowable "very high internal phase emulsions" having excellent sensory properties by addition of 0.01 to 10% of suitable cationic polymers. The aqueous phase of the preparations comprises alcohols, diols or polyols. The document provides water in oil emulsion system where a stable HIP emulsion system is formed for active delivery of the active ingredients selected from the carotenoids beta carotene and lycopene.
The prior art documents as mentioned above provide the ingredients like silicone fluids, blends, polymers systems etc. However none of the prior art documents disclose about the stable delivery of the product. These ingredients of the prior art could not prevent the discoloration of the product, the ingredients of the prior art also does not report about the achievement of the stability of the actives at low concentration and the desired sensory feel.
The prior art does not provide any solution to achieve the stability of the skin care formulation at a high temperature tolerance.
Thus there is a need to provide a stable skin care composition in which the activity of the actives in the formulation remains stable when exposed to high temperature for long time.
The inventors have observed that when colored actives like β carotene and lycopene added to the skin care composition and exposed to various time and temperature study, results in discoloration and instability with respect to its available activity in the product. This instability results in unacceptability of the product by the consumer. It also offers competitive disadvantages with respect to delivery of actives for the desire efficacy over period of time post it is manufacture.
OBJECTS OF THE INVENTION
It is an object of the invention to overcome the drawback of the prior art.
It is another object of the invention to provide a skin care composition comprising HIP emulsion as complexing agent comprising Cyclopentasiloxane, Dimethicone, crosspolymer of Dimethicone Laureth-23 and Laureth –4, and β carotene, lycopene and other uncolored, unstable actives at low concentration.
It is another object of the invention to provide a novel stabilized skin care composition comprising colored and colorless active ingredients.

SUMMARY OF THE INEVNTION
According to one aspect of the present invention, there is provided a stable skin care composition comprising high interfacial phase emulsification system (HIP) in complex with β carotene and lycopene such that β carotene and lycopene are in weight ratio of 80:20 and said complex has pH of 4 to 9 being formed at 8000 to 12, 000 RPM for 30 seconds to 30 minutes.
According to another aspect of the present invention, there is provided a process for preparation of a stable skin care composition comprising the steps of,
i) mixing of high interfacial phase emulsification system (HIP) in an amount of 0.0001-0.001 % w/w/, and combination of β carotene and lycopene in a ratio by weight of 80:20,
ii) stirring the said mixture at 8000-12,000 RPM for 30 seconds to 30 minutes to prepare a stable complex for skin care formulation, and
iii) maintaining the pH of the complex of 4-9.

DETAILED DESCRIPTION OF THE INVENTION
The present invention provides novel skin care composition that prevents discoloration of the actives and the formulation is able to achieve the stabilization in delivery of beta-carotene and lycopene with acceptable sensory feel.
None of the prior art provides stable delivery of the carotenes in a particular weight ratio of 80:20 at a particular pH and at the same time maintaining the stable delivery of the active ingredients as does the present invention.
The present invention relates to skin care composition comprising HIP emulsion as complexing agent comprising Cyclopentasiloxane, Dimethicone, Crosspolymer of Dimethicone Laureth-23 and Laureth-4. The present invention aims to provide a stable complex system where the skin care composition of the present invention comprises a complex of the high interfacial phase emulsification system (HIP) with the actives. When colored β carotene and lycopene are added to the high interfacial phase emulsification system (HIP) at specific stage of manufacturing, it forms a structured complex yielding acceptable aesthetic of the product. When such skin care formulation is exposed to high temperature for long time the activity of the actives in the formulation is stable.
The active complex is formed by the following activity.
When HIP system as mentioned above is subjected to specific external high shear while maintaining the temperature at 30°C, preferably higher revolution per minute (RPM) between 8000–12,000 for 30 seconds to 30 minutes, more preferably 8000-9000 RPM, for up to 30 minutes, the core of the HIP emulsion expands and the actives gets physically locked-in when added at this point of time. Once the external shear is reduced, due to contraction of the HIP emulsion system, the stable complex of active with HIP is formed. The inventors have found that HIP complex prepared at RPM beyond the specific RPM as mentioned above could not offer the color stabilization activity. The inventors have found that at 100 RPM (lower mechanical energy), the opening of HIP structure begins to form a heterogeneous HIP complex with beta-carotene and lycopene. The complete opening of the HIP structure takes place only at 8000-12,000 RPM (higher mechanical energy).
The composition of β-carotene and lycopene is 80:20. The percentage of HIP complex used in the formulation is 0.0001 to 0.01%. When this complex is added to the skin care composition at specific low shear rate and at specific stage of formulation process i.e. temperature and pH, the stable skin care composition is formed having active complex in it which is stable at 50°C without color change while retaining activity of actives.
It was also found that the HIP complex is stable at pH between 4 and 9 and it breaks when pH is reduced below 4 and above 9.
The other conventional ingredients of the skin care composition of the present invention is selected from chelating agents, humectants, emulsifiers, skin penetration enhancer, solubilizer, coemulsifier, skin nourishment agent, occlusive agents, sunscreen, emollients, preservatives, skin conditioning agents, thickener, HIP base, sensory feel enhancement agents, moisturizing agent etc. Some of the conventional ingredients used are disodium EDTA, glycerin, steareth, cetyl alcohol, paraffin, etc.
The other conventional ingredients of the skin care composition comprise from about 2.0 wt% to about 80 wt%, preferably from about 3.0 wt% to about 75.0 wt%.
The present invention is now demonstrated by way of illustrative non - limiting examples. Other variations as may be obvious to one skilled in the art may be made in compounds, formulations, and methods described herein without departing from the essential features of the invention. These and such others may be considered illustrative and non restrictive to the scope of the present invention.
Example 1
A skin care composition comprising the HIP in complex with Beta-carotene and Lycopene was formed with the following ingredients as in Table 1. The HIP components were mixed. The combination of β carotene and lycopene was added and the mixture was stirred at 9000 RPM for 30 minutes to prepare a stable complex for skin care formulation. The pH of the complex was maintained at 4-9. All the values are expressed in weight percentages

Table 1
INCI Name Material purpose Weight %
Aqua Aqueous phase Q.S. to 100
Disodium EDTA Chelating agent 0.05
aGlycerin aHumectants a2.86
Steareth-21 Emulsifier 2.40
Steareth-2 Emulsifier 1.20
Isopropyl Palmitate Skin penetration enhancer 1.50
Propylene Glycol Solubilizer 0.50
Cetyl Alcohol Co-emulsifier 0.50
aTocopheryl Acetate aSkin nourishment agent a0.72
Petrolatum Occlusive agent 0.50
Paraffin Occlusive agent 1.25
aEthylhexyl Methoxycinnamate aSunscreen a1.00
Mineral Oil Emollient 18.00
Methylparaben Preservative 0.16
Propylparaben Preservative 0.04
aHydrogenated Avocado Oil aSkin conditioning agent a0.50
Acrylates/Acrylamide Copolymer (and) Mineral Oil (and) Polysorbate 85 Thickener 2.20
Cyclopentasiloxane, Dimethiconol,Dimethicone Crosspolymer and Phenyltrimethicone Blend Sensory feel enhancement agent 1.42
B carotene Skin nourishment agent 0.008
Lycopene Skin nourishment agent 0.002
Cyclopentasiloxane, Dimethicone, crosspolymer of Dimethicone Laureth-23 and Laureth – 4 HIP base 4.99
Phenoxyethanol Preservative 0.20
PEG/PPG-8/3 Di isostearate Emollient 1.00
aD Panthenol aMoisturizing agent a0.50
aHydroxyethyl Urea aMoisturizing agent a1.00
Fragrance Perfume 0.40
Total 100.00
Note: a Colorless actives

It was found that the composition was stable over 3 months at 40°C and 50°C, which is considered as an equivalent shelf life of product of 18 months at room temperature.
Example 2
In order to assess the effect of pH on the compositions of the present invention, various compositions with the general components of Example 1 were prepared and the pH was varied to see the effect of the same.
The results are depicted in Table 2

Table 2; The effect of pH on the appearance of with HIP complex
S.no Description pH Observation
1 Cyclopentasiloxane, Dimethicone, Crosspolymer of Dimethicone Laureth-23 (HIP) 4.09 White colored compound
2 HIP + 0.01% % (B carotene 80% and lycopene 20%) complex: (HIP Complex) as is pH 3.99 Orange colored glossy compound
3 HIP + 0.01% % (B carotene 80% and lycopene 20%) complex: (HIP Complex) pH adjusted with 0.0001gm of Triethanol amine in HIP complex 4.42 Orange colored glossy compound
4 HIP + 0.01% % (B carotene 80% and lycopene 20%) complex: (HIP Complex) pH adjusted with 0.0002gm of Triethanol amine in HIP complex 6.97 Orange colored glossy compound
5 HIP + 0.01% % (B carotene 80% and lycopene 20%) complex: (HIP Complex) pH adjusted
with 0.02gm of Triethanol amine in HIP complex 8.99 Orange colored glossy compound
6 HIP + 0.01% % (B carotene 80% and lycopene 20%) complex: (HIP Complex) pH adjusted with 0.01gm of Triethanol amine in HIP complex 9.32 Compound found to be hazy

It is thus inferred from Table 2 that beyond pH of 4 to 9 the composition is not stable.
Example 3
A skin care composition according to the present invention is prepared using the same components of Example 1 but the emulsion is prepared by exposure to different RPM such that different level of expansion is obtained. The different observations measured at different revolutions per minute as depicted in Table 3 which shows the role of expansion at exposure to various RPMs for making the same composition.
Table3: The effect of RPM on the appearance on the HIP Complex
S.no Description RPM Observation
1 HIP + 5% (B carotene 80% and lycopene 20%) complex: (HIP Complex) 100-500 Heterogeneous mass with opaque buff orange appearance
2 HIP + 5% (B carotene 80% and lycopene 20%) complex: (HIP Complex) 2000-3500 Heterogeneous mass with opaque buff orange appearance
3 HIP + 5% (B carotene 80% and lycopene 20%) complex: (HIP Complex) 5000-7000 Heterogeneous mass with opaque buff orange appearance
4 HIP + 5% (B carotene 80% and lycopene 20%) complex: (HIP Complex) 8000-10,000 Homogeneous mass with translucent orange appearance
5 HIP + 5% (B carotene 80% and lycopene 20%) complex: (HIP Complex) 10000-12000 Homogeneous mass with translucent orange appearance

It is thus evident from Table 3, that 100 RPM i.e. at a lower mechanical energy, opening of HIP structure begins to form a heterogeneous HIP complex with beta-carotene and lycopene. The complete opening of the HIP structure takes place only at the RPM of 8,000 to 12,000 i.e. higher mechanical energy. At this point of high RPM the high molecular weight beta-carotene and lycopene compounds enters the HIP structures to form a homogenous mass with translucent orange color appearance.
The above Table 3 indicates that at the range of 8000-12000 RPM, the activity was observed to be significant.

Example 4
In order to assess and evaluate the stability of the actives, different compositions were prepared with or without the HIP complex. The composition of β-carotene and lycopene is 80:20; and the loading of this composition is 0.001% to 0.01%.

Table 4 Stability of the total carotene actives in the formulation with and without HIP complex and other antioxidant stabilizer.
Time Temperature Total % carotenoids (beta carotene and lycopene)

Week 0C HIP complex #A02811 with 0.0001% (80:20) (Beta carotene : Lycopene HIP complex #A02811 with 0.001% (80:20) (Beta carotene : Lycopene HIP complex #A02811 with 0.01% (80:20) (Beta carotene : Lycopene Without HIP complex with 0.01% (80:20) (Beta carotene: Lycopene 0.1% and0.05% of sodium meta bi sulphite 0.1% and0.05% butylated hydroxy toluene
4 5 0.000078 0.000330 0.000442 Not detectable (ND) ND ND
RT 0.000066 0.000237 0.000292 Not detectable ND ND
40 0.000019 0.000076 0.000112 Not detectable ND ND
Color and appearance Orange color intact Discoloration observed
8
5 0.000048 0.0002503 0.0003408 Not detectable (ND) ND ND
RT 0.000015 0.000087 0.000114 Not detectable ND ND
40 ND 0.000015 0.0000072 Not detectable ND ND
Color and appearance Orange color intact Discoloration observed

Table 4 depicts the specific conditions for evaluating the effect of β carotene and lycopene.

Table 4 provides concentration of the actives measured in percent weight by weight by using High Performance Liquid Chromatography, for various samples over period of time and temperature to determine the stability of the actives.
Table 4 shows that the role of HIP in the stabilization in comparison with product without HIP or any other conventional anti oxidant stabilizer. The results show that the product with HIP provides the best result. The data of Table 4 indicates that the HIP complex of beta- carotene and lycopene is stable as compared to the one without HIP. Therefore, HIP complex not only mask the color but also improves stability of the actives in the formulation.

WE CLAIM:
1. A stable skin care composition comprising high interfacial phase emulsification system (HIP) in complex with β carotene and lycopene such that β carotene and lycopene are in weight ratio of 80:20 and said complex having pH of 4 to 9 being formed at 8000 to 12, 000 RPM for 30 seconds to 30 minutes.
2. The skin care composition as claimed in claim 1, wherein the said HIP comprises Cyclopentasiloxane, Dimethicone, crosspolymer of Dimethicone Laureth-23 and Laureth-4.
3. The skin care composition as claimed in claim 1 wherein said HIP is present in amount of 0.0001-0.01% w/w, preferably 0.001-0.01% w/w.
4. The skin care composition as claimed in claim 1 wherein the complex is formed at 8000-9000 RPM for 30 minutes.
5. The skin care composition as claimed in claim 1 which further comprises conventional ingredients selected from chelating agents, humectants, emulsifiers, skin penetration enhancer, solubilizer, coemulsifier, skin nourishment agent, occlusive agents, sunscreen, emollients, preservatives, skin conditioning agents, thickener, HIP base, sensory feel enhancement agents, moisturizing agents.
6. The skin care composition as claimed in claim 5, wherein the said conventional ingredients are present in an amount of about 2.0 wt% to about 80.0 wt%, preferably in an amount of about 3.0 wt% to about 75.0 wt%.
7. A process to prepare a stable skin care composition, said process comprising steps of:
i. mixing of high interfacial phase emulsification system (HIP) in an amount of 0.0001-0.001 % w/w/, and combination of β carotene and lycopene in a ratio by weight of 80:20;
ii. stirring the said mixture at 8000-12,000 RPM for 30 seconds to 30 minutes to prepare a stable complex for skin care formulation; and
iii. maintaining the pH of the complex of 4-9.
8. The process as claimed in claim 7 which further comprises adding other/conventional ingredients to get a stabilized skin care formulation.

9. The process as claimed in claim 7, wherein the complex is rotated at 8000 to 9000 RPM for 30 minutes.

10. A personal care formulation and a process for preparation of the same as described herein with reference to examples.

ABSTRACT

A stable skin care composition comprising high interfacial phase emulsification system (HIP) in complex with β carotene and lycopene such that β carotene and lycopene are in weight ratio of 80:20.The complex has pH of 4 to 9 being formed at 8000 to 12, 000 RPM for 30 seconds to 30 minutes. A process to prepare a stable skin care composition comprising steps of, mixing of high interfacial phase emulsification system in an amount of 0.0001-0.001 % w/w, and combination of β carotene and lycopene in a ratio by weight of 80:20, stirring the said mixture at 8000-12,000 RPM for 30 seconds to 30 minutes to prepare a stable complex for skin care formulation and maintaining the pH of the complex of 4-9.