Field of invention
The present invention relates to oil gelling system for liquid oils. More specifically the present invention relates to gelling of vegetable oils.
Background and prior art
There are various gelling agents are known in the arts for gelling various oils.
WO2008055250 discloses an orally dispersible, substantially water-free edible oil-based gel composition for food use, that typically contains between 74% and 99% by weight triglyceride-based edible oil, up to 2.0% by weight hydrophilic microparticulate silicon dioxide, between 0.1% and 1.0% by weight of at least one edible polyol, less than 1% by weight water and less than 25% by weight of additional suspended solids. The polyol and the silicon dioxide in '250 is fully dispersed in the oil-based composition to cause gelling of the edible oil. The triglyceride-based edible oil in '250 includes olive oil, canola oil, safflower oil, sunflower oil, corn oil, cottonseed oil, soybean oil, peanut oil, palm oil, fractions of palm oil, palm kernel oil, flaxseed oil, etc. The hydrophilic microparticulate silicon dioxide includes fumed silica, amorphous silica gel, pyrogenic silica, colloidal silica, silica aerogel, or crystalline silica, etc. the polyol includes glycerol, fatty acid monoglycerides, etc.
JP 3161448 discloses powdery or granular composition containing oil and fat, free from bleeding of oil and fat even at a high content of oil and fat and keeping sufficiently high strength in a drug-preparation process by using an oil and fat, a base for including oil and fat, a polyol, a base agent for absorbing oil and fat and a binder at specific ratios. The composition comprises (A) l-70wt.% of oil and fat such as vegetable oil and pharmaceutical synthetic oil, (B) 30-90wt.% of a base for including oil and fat, e.g. partially hydrolyzed starch, hydrophilic protein or hydrophilic polysaccharide, (C) l-20wt.% of a polyol, preferably a polyol which is liquid at ordinary temperature, especially glycerol, (D) l-20wt.% of a base for absorbing oil and fat, preferably light silica and (E) 0.1-15wt.% of a binder, preferably polyvinyl pyrrolidone.
JP 2005247808 discloses an oily cosmetic for skin care, excellent in usability, for example,

having a matt feeling, without being sticky, shiny, or oily, while maintaining a moist feeling, an effect of moisturizing skin, etc. The oily cosmetic for the skin care contains (a) an oil component containing one, two, or more kinds of nonvolatile oil components selected from a hydrocarbon oil, an ester oil, and a vegetable oil as main components and (b) one, two, or more kinds powders selected from a resin powder and silica in an amount of 15-55 mass%, wherein the cosmetic has a hardness of >=15, when measured by a rheometer at 25°C. Further, (c) a solid wax and an oil gelling agent, (d) a component unstable in the presence of water (such as a vitamin A derivative and a vitamin C derivative), and (e) a perfume may be mixed into the cosmetic, if desired.
Preparation and Evaluation of a New Nano Pharmaceutical Excipients and Drug Delivery System Based in Polyvinylpyrrolidone and Silicate, J Pharm Pharmaceut Sci (www.cspsCanada.org) 14(1) 17 - 35, 2010 discloses nanocomposite prepared by clay/PVP K-30 intercalation as a new matrix for sustained release. It discloses that the combination of polymeric materials as HPMC (hydroxypropyl methylcellulose) and PVP (polyvinylpyrrolidone) with inorganic silicate nanolamellae may provide new compounds named nanocomposites, which present more physically stability with improved properties for pharmaceutical purposes (i.e. compactability, solubility and other physical properties) compared with the initial materials.
US4455331 discloses a coating composition of a binder of film-forming constituents and nonaqueous liquid carrier, wherein the binder is a film-forming resin containing reactive carboxyl groups, hydroxyl groups, amide groups, glycidyl groups or a mixture of any of these groups and a crosslinking agent; and in addition the composition contains about 0.1-10% by weight, based on the weight of the binder, of a rheology control additive of (1) colloidal silica and (2) a polyvinyl pyrrolidone having a weight average molecular weight of about 3,000-500,000.
However these are either not effective in gelling of vegetable oils or have cumbersome manufacturing process such as heating and critical controls.

Accordingly there is a need to provide effective gelling of vegetable oils and a system which can be used for delivery of various anhydrous personal care benefits with reduction of oiliness and greasiness along with improved water repellence.
Object of the invention
It is an object of the present invention to overcome the drawback of the prior art.
It is an objective of the present invention to provide the synergistic effect of alkylated polyvinyl pyrrolidone in effective gelling of vegetable oils, particularly low freezing point triglycerides such as Almond oil, soybean oil, Sesame oils etc.
It is yet another object of the present invention to provide an easy manufacturing process for gelling vegetable oils which negates the cumbersome manufacturing process such as heating and other critical controls.
It is a further, object of the present invention to provide effective gelling format for delivery of vegetable oils wherever the gelled oils are required.
It is also another object of the present invention to provide effective gelling system that can be applied in various products ranging from cosmetics, personal care, skin care, non-FMCG products, pharmaceutical, nutraceutical, automobile or the like.
It is yet another object of the present invention to preclude addition of higher amount of fumed silica to form the desired base / foundation that can be incorporated into various product forms.
Brief Description of Accompanying Figures
Fig.l illustrates products containing gels formed with (A) only fumed silica, (B) only alkylated PVP and (C) combination of fumed silica and alkylated PVP (in accordance with the present invention).

Fig.2 illustrates Sweet almond oil (A) and Gelled sweet almond oil (B) formed by the addition of fumed silica and alkylated PVP in the ratio of 5:1
Fig.3 illustrates Sunflower oil (A) and Gelled sunflower oil (B) by the addition of fumed silica and alkylated PVP in the ratio of 6:1
Fig.4 illustrates Soyabean oil (A) and Gelled soyabean oil (B) by the addition of fumed silica and alkylated PVP in the ratio of 6:1
Summary of the Invention
According to one aspect of the present invention there is provided a gelling system for gelling of liquid oils comprising a synergistic combination of high absorbent fumed silica and alkylated polyvinyl pyrrolidones such that said high absorbent fumed silica is combined with said alkylated polyvinyl pyrrolidones in a ratio ranging from 5: 1 to 7:1.
According to another aspect of the present invention there is provided a process for preparing the
gelling system in accordance with the present invention comprising steps of:
i) adding fumed silica to liquid oils under slow stirring;
ii) adding alkylated polyvinyl pyrrolidone to the mixture of step (i); and iii) slightly warming the mixture of step (ii) until the alkylated polyvinyl pyrrolidone dissolves completely.
Detailed Description of the Invention
The present invention provides a synergistic combination of high absorbent fumed silica and alkylated polyvinyl pyrrolidones which provides an effective gelling system for liquid oils, more specifically vegetable oils. The present invention is more applicable to low freezing point triglycerides such as almond oil, soybean oil, sesame oils etc., which can be used in various cosmetic applications. The present invention provides system for gelling of vegetable oils that

has wide range of personal care applications especially in reduction of oiliness and greasiness along with improved water repellence. The gelling agent according to the present invention provides excellent feel to the user with ease of spreading, excellent luster and moisturizing feel.
Fumed silica is known to be used as a gelling agent, however the present inventors have surprisingly found that addition of very small amount of alkylated polyvinyl pyrrolidones reduce the quantity of fumed silica requirement as gelling agent.
The gelling system accordingly to the present invention thus comprises high absorbent fumed silica and alkylated polyvinyl pyrrolidones where the two components are combined in a ratio ranging from ranging from 5: 1 to 7:1, preferably at 5:1, more preferably at 6:1 and most preferably at 7:1. Beyond this range, gellation might occur; however, the resultant gels are not desirable for they are difficult to process in the final product and are also aesthetically not desirable for example they are either too oily or too viscous. It has been found that products containing gels made of only fumed silica (Fig. 1-A) have high viscosity and accordingly there are difficulties in processing the product and are also aesthetically undesirable. Further products containing gels made of only alkylated PVP (Fig. 1-B) are too oily and aesthetically undesirable. The present inventors have found that a combination of fumed silica and alkylated PVP (Fig. 1-C) when used as a gelling system, in a ratio as mentioned above, provides desirable gellation which is easy to process in the final product, is stable and at the same time aesthetically desirable such as provides excellent feel to the user with ease of spreading, excellent luster and moisturizing feel.
The liquid oils that can be effectively gelled by the gelling system of the present invention include but not limited to almond oil, soybean oil, sesame oil, almond oil, beech nut oil, cashew oil, hazelnut oil, macadamia oil, pine nut oil, pistachio oil, walnut oil, amaranth oil, apricot oil, apple seed oil, avocado oil, babassu oil, cocoa butter, grape seed oil, hemp oil, mustard oil papaya seed oil, rice bran oil, shea nuts, shea butter, tea seed oil (Camellia oil), rapeseed oils, tobacco seed oil, tomato seed oil, wheat germ oil, jojoba oil, rosewood oil, sandalwood oil, eucalyptus oil, cedarwood oil, lemon oil, basil oil, bergamot oil, neroli oil, nutmeg oil, cassia oil, orange oil, chamomile oil, patchouli oil, petitgrain oil, rose oil, clove oil, coriander oil, rosemary oil, sage oil, gardenia oil, geranium oil, vetiver oil, jasmine oil, lavender oil, apricot oil, argan

oil, avocado oil, borage oil, castor oil, coconut butter, coconut oil, evening primrose oil, grapeseed oil, hemp seed oil, moringa oil, mustard seed oil, neem oil, olive oil, palm kernel oil, peach kernel oil, rice bran oil, rosehip oil, sesame oil, sunflower oil etc.
The alkylated polyvinyl pyrrolidones of the present invention includes Copolymers of vinylpyrrolidone and long-chain a-olefins, Tricontanyl PVP, and mixtures thereof. Most preferably the present invention contemplates the use of VP/Eicosene Copolymer.
The gelling system of the present invention is prepared by the process comprising steps of: i) adding fumed silica to vegetable oil under slow stirring. ii) adding alkylated polyvinyl pyrrolidone to the mixture of step (i) and iii) slightly warming the mixture of step (ii) until the alkylated polyvinyl pyrrolidone dissolves completely.
With recent trend of natural cosmetics, the present invention thus enables vegetable oils such as olive oil, almond oil, soybean oil etc to be delivered in gel format and used as delivery system for personal care ingredients or products wherever the gelled oils are required. The gelling system can be easily incorporated into various applications like cosmetics, personal care, skin care, non-FMCG products, pharmaceutical, automobile, nutraceutical and the like.
The present invention is illustrated below by non-limiting examples.
Example 1
The gelling system of the present invention is prepared by the process comprising steps of: i) adding 5.56g of fumed silica to 93.46 of almond oil under slow stirring. ii) adding 0.98g of VP/Eicosene copolymer to the mixture of step (i) and iii) slightly warming the mixture of step (ii) to about 50°C until the alkylated polyvinyl pyrrolidone dissolves completely.

Example 2
A lip balm composition is prepared comprising combination of the low freezing point triglycerides, fumed silica and VP/Eicosene copolymer in accordance with the process illustrated in Example 1. The composition of the lip balm composition is provided in Table 1.
Table 1: Lip Balm Composition containing low freezing point triglycerides e.g. Sweet almond oil.

Example 3
Gelling systems with varying amounts of fumed silica and alkylated PVP (as mentioned in Table 2) were prepared in accordance with the process of Example 1. Different types of oils (viz., low freezing point triglycerides e.g. Sweet almond oil, Sunflower oil, Soyabean oil) have been used with varying amounts of fumed silica and VP/Eicosene copolymer and their combinations and the gelling effect is observed.
Table 2 Amounts of fumed silica and alkylated PVP (VP/Eicosene copolymer) mixed with different types of oils.



The gelling effect was observed for all of the above mentioned experiments. Fig.2 illustrates the gelling effect of Sweet almond oil in non-gelled form (A) and gelled form (B) where the gelling system comprises fumed silica and VP/Eicosene copolymer in the ratio of 5:1. Fig.3 illustrates the gelling effect of Sunflower oil in non-gelled form (A) and gelled form (B) where the gelling system comprises fumed silica and VP/Eicosene copolymer is in the ratio of 6:1. Fig. 4 illustrates the gelling effect of Soyabean oil in non-gelled form (A) and gelled form (B) where the gelling system comprises fumed silica and VP/Eicosene copolymer in the ratio of 6:1.
It was observed that to provide the effective gelling for sweet almond oil 10.129% w/w of fumed silica was required in absence of VP/Eicosene copolymer. However the requirement of fumed silica came down to 7.197% (about 3% reduction) along with the addition of VP/Eicosene copolymer at 1.39%. This shows that the present invention precludes the amount of adding higher amounts of fumed silica to form the desired base / foundation that can be incorporated into various product forms.
Similar results were also observed when the ratio of fumed silica to VP/Eicosene copolymer was changed to 5:1. It was observed that to achieve the desired gelling effect for Sweet almond oil, the amount of fumed silica is reduced from 10 to 5.56% (about 4.5% reduction) with the inclusion of VP/Eicosene copolymer at 0.97%.
Correspondingly, to achieve the desired gelling effect of sunflower oil and soyabean oil the amount of fumed silica is required just at the level of 6.008 and 6.263 respectively with the addition of VP/Eicosene copolymer at 1.058 and 1.145% only.
Accordingly from the above experiments it can be concluded that the gelling system in accordance with the present invention precludes the amount of adding higher amounts of fumed silica while providing effective gellation for triglyceride oil.

Example 4
Experiments were performed in order to evaluate the criticality of presence of fumed silica and alkylated polyvinyl pyrrolidone (VP/Eicosene copolymer) in gelling system in accordance with the present invention.
The present inventors had conducted experiments for gelling of various types of oils such as sweet almond oil, sunflower oil or soyabean oil using only fumed silica and found that desired gellation was observed at amounts as mentioned in Table 3.
Table 3

Similar type of experiments as above were also performed with only alkylated pyrrolidone (VP/Eicosene copolymer) in varying amounts as mentioned in Table 4.

In the aforementioned experiments no gelling effect was observed.

This shows that alkylated PVP in the above amounts did not provide gelling effect, however when combined with fumed silica not only provided effective gellation but also precluded the requirement for high amount of silica in the gelling system.

WE CLAIM:
1. A gelling system for gelling of liquid oils comprising a combination of high absorbent fumed silica and alkylated polyvinyl pyrrolidones such that the said high absorbent fumed silica is combined with said alkylated polyvinyl pyrrolidones in a ratio ranging from 5: 1 to 7:1.
2. The gelling system for gelling of liquid oils as claimed in claim 1, wherein the said high absorbent fumed silica is combined with said alkylated polyvinyl pyrrolidones in a ratio preferably at 5:1, more preferably at 6:1 and most preferably at 7:1.
3. The gelling system for gelling of liquid oils as claimed in claim 1, wherein said liquid oils are selected from low freezing point triglycerides.
4. The gelling system for gelling of liquid oils as claimed in claim 3, wherein said triglycerides are selected from sweet almond oil, sunflower oil, soyabean oil and mixtures thereof.
5. The gelling system for gelling of liquid oils as claimed in claim 1, wherein said liquid oils are selected from the group comprising almond oil, soybean oil, sesame oil, beech nut oil, cashew oil, hazelnut oil, macadamia oil, pine nut oil, pistachio oil, walnut oil, amaranth oil, apricot oil, apple seed oil, avocado oil, babassu oil, cocoa butter, grape seed oil, hemp oil, mustard oil papaya seed oil, rice bran oil, shea nuts, shea butter, tea seed oil (Camellia oil), rapeseed oils, tobacco seed oil, tomato seed oil, wheat germ oil, jojoba oil, rosewood oil, sandalwood oil, eucalyptus oil, cedarwood oil, lemon oil, basil oil, bergamot oil, neroli oil, nutmeg oil, cassia oil, orange oil, chamomile oil, patchouli oil, petitgrain oil, rose oil, clove oil, coriander oil, rosemary oil, sage oil, gardenia oil, geranium oil, vetiver oil, jasmine oil, lavender oil, apricot oil, argan oil, avocado oil, borage oil, castor oil, coconut butter, coconut oil, evening primrose oil, grapeseed oil,

hemp seed oil, moringa oil, mustard seed oil, neem oil, olive oil, palm kernel oil, peach kernel oil, rice bran oil, rosehip oil, sesame oil, sunflower oil, and mixtures thereof.
6. The gelling system for gelling of liquid oils as claimed in any of the preceding claims, wherein said alkylated polyvinyl pyrrolidones is selected from Copolymers of vinylpyrrolidone and long-chain a-olefins, VP/Eicosene Copolymer, Tricontanyl PVP and mixtures thereof.
7. A process for preparing the gelling system as claimed in any of the preceding claims comprising steps of:
i) adding fumed silica to liquid oils under slow stirring,
ii) adding alkylated polyvinyl pyrrolidone to the mixture of step (i) and iii) slightly warming the mixture of step (ii) until the alkylated polyvinyl pyrrolidone dissolves completely.
8. The gelling system as claimed in claim 1, the said system being incorporated into
applications selected from cosmetics, personal care, skin care, non-FMCG products,
pharmaceutical, automobile and nutraceutical.