HK1235699B - Nanoemulsions having reversible continuous and dispersed phases - Google Patents

Description

Nanoemulsions with reversible continuous and dispersed phases

Background Art

There are two types of nanoemulsions, namely, oil-in-water (o/w) nanoemulsions and water-in-oil (w/o) nanoemulsions. O/w nanoemulsions have a continuous water phase and a dispersed oil phase, while w/o nanoemulsions have a continuous oil phase and a dispersed water phase.

These two types of nanoemulsions are stabilized by emulsifiers with different hydrophilic-lipophilic balance (HLB) values. O/w nanoemulsions are stabilized by emulsifiers with HLB values of 8 to 28, and w/o dispersions are stabilized by emulsifiers with HLB values of 3 to 6. Therefore, they cannot be easily converted into each other.

Lack of easy convertibility can be problematic. When the water content of an o/w nanoemulsion decreases, it can disintegrate. Similarly, when the oil content of a w/o nanoemulsion decreases, it can disintegrate.

Therefore, it is necessary to develop a nanoemulsion whose continuous phase and dispersed phase can be easily converted into each other via the same emulsifier contained in the nanoemulsion.

Summary of the Invention

Disclosed herein is a nanoemulsion containing reversible continuous and dispersed phases.

The nanoemulsion of the present invention comprises an aqueous phase and an oil phase, with the weight ratio of the aqueous phase to the oil phase being 1:40 to 100:1. In the nanoemulsion, the aqueous phase is dispersed in the oil phase in the form of nanosized droplets, or the oil phase is dispersed in the aqueous phase in the form of nanosized droplets. The aqueous phase, which accounts for at least 2.5% by weight of the nanoemulsion, contains water or an aqueous solution and a water-soluble organic nanostructure stabilizer. The water or aqueous solution comprises less than 75% by weight of the aqueous phase, and the water-soluble organic nanostructure stabilizer comprises less than 99% by weight of the aqueous phase. The oil phase comprises oil or an oil solution, an organogel thickener, and a hydrophilic surfactant having an HLB value greater than 8.0. The oil or oil solution comprises less than 80% by weight of the oil phase, the organogel thickener comprises less than 60% by weight of the oil phase, and the hydrophilic surfactant comprises less than 60% by weight of the oil phase. This nanoemulsion can be used as a carrier of active ingredients in cosmetic, food or pharmaceutical compositions.

The present invention also provides a method for preparing the nanoemulsion. The method comprises the following steps: (1) mixing water or an aqueous solution with a water-soluble organic nanostructure stabilizer to form an aqueous phase, wherein the water or aqueous solution comprises less than 75% by weight of the aqueous phase and the water-soluble organic nanostructure stabilizer comprises less than 99% by weight of the aqueous phase; (2) mixing an oil or an oil solution, an organic thickener, and a hydrophilic surfactant having a hydrophilic-lipophilic balance greater than 8.0 to form an oil phase, wherein the oil or oil solution comprises less than 80% by weight of the oil phase, the organic gel thickener comprises less than 60% by weight of the oil phase, and the hydrophilic surfactant comprises less than 60% by weight of the oil phase; and (3) mixing the aqueous phase with the oil phase to form a nanoemulsion, wherein the weight ratio of the aqueous phase to the oil phase is from 1:40 to 100:1, wherein the water or aqueous solution comprises less than 74% by weight of the nanoemulsion. Each of the mixing steps is performed at a suitable temperature, for example, from 5°C to 95°C.

In the nanoemulsion thus prepared, the aqueous phase is dispersed in the oil phase in the form of nanoscale droplets, or the oil phase is dispersed in the aqueous phase in the form of nanoscale droplets. In other words, the continuous and dispersed phases in the nanoemulsion are reversible.

The details of one or more embodiments are set forth in the description below. Other features, objects, and advantages of the embodiments will become apparent from the description and claims.

DETAILED DESCRIPTION

The present invention is based, at least in part, on the unexpected discovery that nanoemulsions containing hydrophilic surfactants having an HLB value greater than 8 can have an aqueous phase dispersed in an oil phase as nanosized droplets, or an oil phase dispersed in an aqueous phase as nanosized droplets. In other words, the nanoemulsions have reversible continuous and dispersed phases.

This nanoemulsion can carry both oil-soluble and water-soluble active ingredients, which is an advantage over existing nanoemulsions. This advantage is particularly important in the preparation of cosmetics, foods, household chemicals, agricultural products, printing products, dyeing products, veterinary products, diagnostic products, vaccines, and pharmaceutical products, as illustrated in the following two examples.

O/W dispersions are preferred for use in cosmetics because they are less viscous and greasy than W/O dispersions and have a desirable water-holding capacity. However, when the cosmetic is applied to the skin or exposed to air, the nanoemulsion in the cosmetic loses water through evaporation. This water loss causes existing O/W nanoemulsions to disintegrate, but the O/W nanoemulsions of the present invention do not. Instead, the latter nanoemulsion slowly transforms into a W/O nanoemulsion, in which the aqueous phase is uniformly dispersed in the oil phase as nanoscale droplets.

Differently, for oil-soluble drugs, w/o dispersions are preferred due to their high loading capacity. However, when a w/o nanoemulsion comes into contact with body fluids, since the body fluids are aqueous, their water content inevitably increases. Consequently, existing w/o nanoemulsions disintegrate. The w/o nanoemulsions of the present invention, on the other hand, slowly transform into o/w nanoemulsions, in which the oil phase is uniformly dispersed in the aqueous phase as nanoscale droplets. Notably, this transformation not only maintains the integrity of the nanoemulsion but also provides for sustained release of the drug therein.

As noted above, the nanoemulsions of the present invention comprise an aqueous phase and an oily phase. In the nanoemulsion, the aqueous phase can be dispersed in the oily phase in the form of nanoscale droplets. Alternatively, the oily phase can be dispersed in the aqueous phase in the form of nanoscale droplets.

The aqueous phase includes a water-soluble organic nanostructure stabilizer. The term "water-soluble organic nanostructure stabilizer" refers to any water-soluble organic component that can stabilize the isotropic structure of the nanoemulsion, thereby producing a thermodynamically stable transparent or translucent nanoemulsion. It can be a water-soluble vitamin, a water-soluble peptide, a water-soluble oligopeptide, a polyol, a water-soluble sugar, a water-soluble oligosaccharide, a disaccharide, a monosaccharide, a hydrogenated carbohydrate, an amino acid, an amino sugar, or a combination thereof. Specific examples include urea, methylsulfonylmethane, hydroxyethyl urea, glucosamine, mannitol, sorbitol, xylitol, lactose, fructose, dextrose, ribose, trehalose, raffinose, maltitol, isomaltose, lactitol, erythritol, inositol, taurine, glycerol, propylene glycol, dipropylene glycol, butylene glycol, hexylene glycol, polyethylene glycol, ethoxydiglycol, carnitine, arginine, sodium pyrrolidone formate, and hydrolyzed collagen.

The oil phase contains oil or oil solution. Vegetable oil, silicone oil, synthetic oil, mineral oil, animal oil, essential oil or its combination can be used to form the oil phase. Specific examples include coconut oil, palm oil, grape seed oil, olive oil, grapefruit oil, linseed oil, avocado oil, evening primrose oil (evening primrose oil), lavender oil, rosemary oil, tea tree oil, eucalyptus oil, horse fat, fish oil, lanolin oil, squalene (squalene), cyclomethicone (cyclomethicone), cyclopentasiloxane, phenyl trimethicone, caprylic acid/capric triglyceride, isopropyl myristate, isostearyl isostearate, decyl oleate, ethylhexyl isononanoate, isohexadecane, octyldodecanol, paraffin oil, polydecene, polyisobutene, menthol or its combination. It should be noted that the oil solution contains one or more oils as the solvent for dissolving one or more oil-soluble solutes.

As also noted above, the oil phase includes a hydrophilic surfactant having an HLB value greater than 8.0. Preferably, the hydrophilic surfactant has an HLB value greater than 10, and more preferably, an HLB value greater than 13. Examples of the hydrophilic surfactant include polyoxyethylene sorbitan fatty acid esters (Tween 20, Tween 21, Tween 60, Tween 61, Tween 65, Tween 80, Tween 81, Tween 85), polyoxyethylene sorbitan fatty acid esters, polyoxyethylene acid ester fatty acid esters (Myri 45, Myri 52, Myri 53, Myri 59), polyoxyethylene acid fatty acid esters (Myri 45, Myri 52, Myri 53, Myri 59), polyoxyethylene alcohol esters (Brij 30, Brij 35, Brij 56, Brij 58, Brij 76, Brij 78, Brij 96, Brij 97, Brij 98, Brij 99), nonylphenol alkoxylates (Witconol ^TM non-ionic surfactants based on nonylphenol), alkyl alkoxylates (Ethylan ^™ family of non-ionic surfactants), Pluronic F-127, PEG dimethicone, polyoxyethylene (40) fatty acid esters, polyoxyethylene (20) sugar fatty acid esters, PEG-15 glyceryl fatty acid esters, PEG-35 hydrogenated castor oil, PEG-40 hydrogenated castor oil, polyglyceryl fatty acid esters, fatty amine derivatives, or combinations thereof.

In addition, the oil phase contains an organogel thickener. The term "organogel thickener" herein refers to any substance that increases viscosity and causes the structured formation of the nanoemulsion. The organogel thickener can be a saturated fatty acid, a fatty acid alcohol, a fatty acid derivative having a melting point greater than 45°C, or a combination thereof. Examples of organogel thickeners include stearic acid, lauric acid, glyceryl monostearate, PEG 6000 Diesterate, monoglycerides, diglycerides, sugar fatty acid esters, propylene glycol fatty acid esters, glycol fatty acid esters, fatty acid hexyldecyl esters, fatty acid alcohols, cetyl stearate, ascorbic acid fatty acid esters, glyceryl fatty acid esters, fatty acid hexyldecyl esters, or a combination thereof.

In one embodiment, the nanoemulsion of the present invention has a water or aqueous solution content of less than 60% by weight of the aqueous phase, and a water-soluble organic nanostructure stabilizer content of less than 70% by weight of the aqueous phase; the oil or oil solution content is 30% to 70% by weight of the oil phase, the organogel thickener content is less than 45% by weight of the oil phase, and the hydrophilic surfactant content is less than 45% by weight of the oil phase; the water or aqueous solution accounts for less than 38% by weight of the nanoemulsion, and the weight ratio of the aqueous phase to the oil phase is 1:3 to 4:1. Preferably, the content of water or aqueous solution is less than 45% by weight of the aqueous phase, and the content of water-soluble organic nanostructure stabilizer is less than 50% by weight of the aqueous phase; the content of oil or oil solution is less than 45% to 65% by weight of the oil phase, the content of organic gel thickener is less than 25% by weight of the oil phase, and the content of hydrophilic surfactant is less than 35% by weight of the oil phase; and the water or aqueous solution accounts for less than 30% by weight of the nanoemulsion, and the weight ratio of the aqueous phase to the oil phase is 1:2 to 3:1.

The nanoemulsions of the present invention are transparent or translucent and are in solid gel form or liquid form at a pH of 3 to 11. In addition, they exhibit nano features, namely, the Tyndall light refraction effect. See Gold and Silver Nanoparticles, Center for Nanoscale Chemical-Electrical-Mechanical Manufacturing Systems, University of Illinois, http://Nano-cemms.illinois.edu/media/content/teaching_mats/online/gold_and_silver_nanoparticles/docs/presentation.pdf.

The nanoemulsions of the present invention, wherein water or an aqueous solution comprises less than 38% by weight of the nanoemulsion, are self-preservative and therefore do not require the inclusion of an antimicrobial preservative. Preservatives generally raise safety concerns because they can cause health hazards ranging from mild headaches to the most serious diseases, such as cancer.

When used in cosmetic, food, and pharmaceutical compositions, the nanoemulsion can carry various active ingredients, for example, terbinafine, diclofenac diethylamide, capsaicin, diazepam, lorazepam, propofol, metronidazole, indomethacin, clotrimazole, ketoconazole, erythromycin, climbazole, actin, bifonazole, miconazole, tolnaftate, clobetasol, econazole, ethyl benzoate, phenytoin, lovastatin, isosorbide dinitrate, nitroglycerin, famotidine, bisabolol, lutein esters, melanin, oil-soluble vitamins, lycopene, resveratrol, ginsenosides, vanillyl butyl ether, curcumin, and CoQ10. Nanoemulsions comprising drugs can be administered via various routes, for example, orally, topically, vaginally, rectally, sublingually, pulmonaryly and parenterally. If desired, certain sweeteners, flavorings, colorings or aromas may also be added.

The present method for preparing the aforementioned nanoemulsions involves first forming an aqueous phase and an oil phase separately, and then mixing the two phases. The aqueous phase can be formed by mixing water or an aqueous solution and a water-soluble organic nanostructure stabilizer by continuous stirring (manually or otherwise), high-speed and high-shear mixing (e.g., using a colloid mill), high-pressure mixing (e.g., using a microfluidizer), or sonication. Oil or an oil solution, an organic thickener, and a hydrophilic surfactant can also be mixed in this manner to form an oil phase. The resulting aqueous and oil phases can then be mixed in a similar manner to form a nanoemulsion. Notably, all mixing steps can be performed at elevated temperatures, e.g., 45°C to 85°C, if desired. Importantly, the oil and aqueous phases thus obtained can be used to prepare o/w nanoemulsions or w/o nanoemulsions, demonstrating that the continuous and dispersed phases are reversible.

Without further detailed description, it is believed that the above description has fully realized the present invention. Therefore, the following examples should be understood to be merely illustrative and not to limit the remainder of the present invention in any way. The publications cited herein are incorporated herein by reference in their entirety.

Example 1: Determination of nanoemulsion type

Place 60 ml of water in a 100-ml beaker. Add the nanoemulsion to be tested dropwise to the water. If the nanoemulsion dispersed in water produces a transparent or translucent solution, the nanoemulsion tested is an o/w nanoemulsion. However, if the nanoemulsion forms oily droplets in water, the nanoemulsion tested is a w/o nanoemulsion. Example 2: Preparation of Coconut Oil Nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 210 grams of purified water, 90 grams of urea, 60 grams of xylitol, 60 grams of trehalose, and 30 grams of methylsulfonylmethane was mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 80 grams of coconut oil, 20 grams of paraffin oil, 50 grams of cyclomethicone (DC-345), 20 grams of beeswax, 10 grams of glyceryl monostearate, 16 grams of stearic acid, 14 grams of sorbitan monostearate, 36 grams of polyethylene glycol sorbitan monostearate, and 42 grams of PEG-40 hydrogenated castor oil were mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

The combination of the above prepared oil phase and water phase in the weight ratio shown in Table 1 below was mixed by constant manual stirring in a 200-ml beaker at 65-75°C for less than 0.5 hours to form a w/o or o/w nanoemulsion.

Table 1

ID 1 2 3 4 Oil phase (g) 120 90 40 25 Aqueous phase (g) 30 60 60 75 Nanoemulsion (g) 150 150 100 100 type w/o w/o o/w o/w Physical appearance translucent transparent transparent transparent

All nanoemulsions were stable at room temperature for at least 3 months and exhibited Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 3: Preparation of palm oil nanoemulsion

The nanoemulsions were prepared following the procedure described below.

150 g of a w/o nanoemulsion consisting of 30 g of an aqueous phase and 120 g of an oily phase was prepared following the procedure described in Example 2, except that palm oil was used instead of coconut oil. The nanoemulsion thus prepared was translucent and stable at room temperature for at least 3 months. It exhibited the Tyndall light refraction effect.

150 g of a w/o nanoemulsion consisting of 60 g of an aqueous phase and 90 g of an oil phase was prepared following the procedure described in Example 2, except that palm oil was used instead of coconut oil. The nanoemulsion thus prepared was transparent and stable at room temperature for at least 3 months. It exhibited the Tyndall refraction effect.

150 g of an o/w nanoemulsion consisting of 60 g of an aqueous phase and 90 g of an oil phase was prepared following the procedure described in Example 2, except that palm oil was used instead of coconut oil. The nanoemulsion thus prepared was transparent and stable at room temperature for at least 3 months. It exhibited the Tyndall light refraction effect.

100 g of an o/w nanoemulsion consisting of 75 g of an aqueous phase and 25 g of an oily phase was prepared following the procedure described in Example 2, except that palm oil was used instead of coconut oil. The nanoemulsion thus prepared was transparent and stable at room temperature for at least 3 months. It exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

All nanoemulsions prepared in this example were tested for antimicrobial effectiveness following the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52.

Example 4: Preparation of horse fat nanoemulsion

The nanoemulsions were prepared following the procedure described below.

150 g of w/o nanoemulsion consisting of 60 g of aqueous phase and 90 g of oil phase was prepared following the procedure described in Example 2 except that horse fat was used instead of coconut oil.

100 g of o/w nanoemulsion consisting of 60 g of aqueous phase and 40 g of oil phase was prepared following the procedure described in Example 2 except that horse fat was used instead of coconut oil.

The nanoemulsions prepared in this way were transparent and stable at room temperature for at least 3 months. They all exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35<51>, Antimicrobial Effectiveness Testing, page 52, and both nanoemulsions prepared in this example passed the antimicrobial test.

Example 5: Preparation of horse fat nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 150 grams of purified water, 150 grams of urea, and 40 grams of mannitol were mixed by constant manual stirring in a beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

The oil phase was prepared following the procedure described in Example 2 except that horse fat was used instead of coconut oil.

Preparation of nanoemulsion

Following the procedure described in Example 2, 150 g of w/o nanoemulsion consisting of 60 g of aqueous phase and 90 g of oil phase was prepared.

Following the procedure described in Example 2, 100 g of an o/w nanoemulsion consisting of 60 g of an aqueous phase and 40 g of an oily phase was prepared.

The nanoemulsions prepared in this way were transparent and stable at room temperature for at least 3 months. They all exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35<51>, Antimicrobial Effectiveness Testing, page 52, and both nanoemulsions prepared in this example passed the antimicrobial test.

Example 6: Preparation of Palm Oil/Squalene Nanoemulsion Containing Only One Hydrophilic Surfactant

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 180 grams of purified water, 100 grams of urea, and 20 grams of butanediol was mixed by constant manual stirring in a 500-ml beaker placed at 65° C. to 75° C. to form an aqueous phase. Preparation of the oil phase of the nanoemulsion

A combination of 100 grams of palm oil, 20 grams of squalene, 25 grams of cyclomethicone (DC-345), 10 grams of beeswax, 20 grams of stearic acid, 16 grams of sorbitan monostearate, and 60 grams of PEG-40 hydrogenated castor oil was mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

The combination of the above prepared oil phase and water phase in the weight ratio shown in Table 2 below was mixed at 65-75°C by constant manual stirring in a 500-ml beaker for up to 0.5 hour to form the nanoemulsion also listed in Table 2.

Table 2

ID 1 2 3 4 Oil phase (g) 105 90 60 30 Aqueous phase (g) 15 60 90 120 Total weight (g) 120 150 150 150 type w/o w/o o/w o/w Physical appearance translucent transparent transparent transparent

All of the above nanoemulsions were stable at room temperature for at least 3 months and exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 7: Preparation of Coconut Oil-Based Pharmaceutical Nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Following the procedure described in Example 2, 50 g of an o/w nanoemulsion was prepared consisting of 29.5 g of an aqueous phase and 20 g of an oil phase in which 0.5 g of an oil-soluble pharmaceutically active ingredient was dissolved. The oil-soluble pharmaceutically active ingredient was terbinafine, diclofenac diethylamine, diethylamine, metronidazole, indomethacin, clotrimazole, or erythromycin.

The six nanoemulsions thus prepared were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 8: Preparation of Palm Oil-Based Pharmaceutical Nanoemulsion

Nanoemulsions were prepared following the procedure described in Example 7, except that palm oil was used instead of coconut oil, and the oil-soluble pharmaceutical active ingredients were terbinafine, diclofenac diethylamide, metroconazole, actin, bifonazole, and miconazole.

The six nanoemulsions thus prepared were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 9: Preparation of essential oil nanoemulsion containing climbazole

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 150 grams of purified water, 150 grams of urea, and 40 grams of propylene glycol were mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 40 grams of tea tree oil, 20 grams of eucalyptus oil, 30 grams of menthol, 50 grams of paraffin oil, 50 grams of cyclomethicone (DC-345), 20 grams of beeswax, 10 grams of glyceryl monostearate, 16 grams of stearic acid, 14 grams of sorbitan monostearate, 36 grams of polyethylene glycol sorbitan monostearate, and 42 grams of PEG-40 hydrogenated castor oil were mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 150 g of w/o nanoemulsion consisting of 60 g of aqueous phase and 90 g of oil phase was prepared.

Following the procedure described in Example 2, 150 g of an o/w nanoemulsion consisting of 90 g of an aqueous phase and 60 g of an oily phase was prepared.

Following the procedure described in Example 2, 100 g of an o/w nanoemulsion consisting of 59 g of an aqueous phase and 40 g of an oil phase in which 1 g of climbazole was dissolved was prepared.

All the above nanoemulsions were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 10: Preparation of an essential oil nanoemulsion having an aqueous phase different from that in Example 9

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 210 grams of purified water, 90 grams of urea, 60 grams of xylitol, 60 grams of trehalose, and 30 grams of methylsulfonylmethane was mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 40 grams of tea tree oil, 20 grams of eucalyptus oil, 30 grams of menthol, 50 grams of paraffin oil, 50 grams of cyclomethicone (DC-345), 20 grams of beeswax, 10 grams of glyceryl monostearate, 16 grams of stearic acid, 14 grams of sorbitan monostearate, 36 grams of polyethylene glycol sorbitan monostearate, and 42 grams of PEG-40 hydrogenated castor oil were mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 150 g of w/o nanoemulsion consisting of 60 g of aqueous phase and 90 g of oil phase was prepared.

Following the procedure described in Example 2, 150 g of an o/w nanoemulsion consisting of 90 g of an aqueous phase and 60 g of an oily phase was prepared.

The two nanoemulsions were transparent and stable at room temperature for at least 3 months. They both exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35<51>, Antimicrobial Effectiveness Testing, page 52, and both nanoemulsions prepared in this example passed the antimicrobial test.

Example 11: Preparation of essential oil nanoemulsion containing tolnaftate or ketoconazole

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 150 grams of purified water, 150 grams of urea, and 40 grams of propylene glycol were mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 50 grams of tea tree oil, 20 grams of eucalyptus oil, 15 grams of menthol, 15 grams of methyl salicylate, 50 grams of cyclomethicone (DC-345), 10 grams of beeswax, 10 grams of lauric acid, 6 grams of stearic acid, 14 grams of sorbitan monostearate, 40 grams of polyoxyethylene glycol (40) stearate, and 40 grams of PEG-40 hydrogenated castor oil were mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 150 g of w/o nanoemulsion consisting of 60 g of aqueous phase and 90 g of oil phase was prepared.

Following the procedure described in Example 2, 150 g of an o/w nanoemulsion consisting of 90 g of an aqueous phase and 60 g of an oily phase was prepared.

Following the procedure described in Example 2, 150 g of a w/o nanoemulsion consisting of 60 g of an aqueous phase and 88.2 g of an oil phase in which 1.8 g of tolnaphthate was dissolved was prepared.

Following the procedure described in Example 2, 150 g of a w/o nanoemulsion consisting of 60 g of an aqueous phase and 88.2 g of an oil phase in which 1.8 g of ketoconazole was dissolved was prepared.

All the above nanoemulsions were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 12: Preparation of fragrance/essential oil nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 150 grams of purified water, 150 grams of urea, and 40 grams of propylene glycol were mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 80 grams of lemon eucalyptus oil, 40 grams of citronella oil, 24 grams of lavender oil, 22 grams of eucalyptus oil, 15 grams of rosemary oil, 15 grams of camphor, 15 grams of menthol, 6 grams of thyme, 10 grams of beeswax, 10 grams of lauric acid, 6 grams of stearic acid, 14 grams of sorbitan monostearate, 40 grams of polyoxyethylene glycol (40) stearate, and 40 grams of PEG-40 hydrogenated castor oil were mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 150 g of w/o nanoemulsion consisting of 60 g of aqueous phase and 90 g of oil phase was prepared.

Following the procedure described in Example 2, 100 g of an o/w nanoemulsion consisting of 60 g of an aqueous phase and 40 g of an oily phase was prepared.

Both nanoemulsions were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35<51>, Antimicrobial Effectiveness Testing, page 52, and both nanoemulsions prepared in this example passed the antimicrobial test.

Example 13: Preparation of Medium- and Long-Chain Oil Nanoemulsion Containing CoQ10

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 150 grams of purified water, 100 grams of glycerin, 80 grams of xylitol, 20 grams of mannitol, and 30 grams of methylsulfonylmethane was mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 170 grams of medium-chain triglyceride oil, 16 grams of stearic acid, 14 grams of sorbitan monostearate, 30 grams of polyethylene glycol sorbitan monostearate, and 30 grams of PEG-40 hydrogenated castor were mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 150 g of a w/o nanoemulsion consisting of 50 g of an aqueous phase and 95 g of an oil phase in which 5 g of CoQ10 was dissolved was prepared.

Following the procedure described in Example 2, 150 g of an o/w nanoemulsion consisting of 90 g of an aqueous phase and 57 g of an oil phase in which 3 g of CoQ10 was dissolved was prepared.

Following the procedure described in Example 2, 153 g of an o/w nanoemulsion consisting of 120 g of an aqueous phase and 30 g of an oil phase in which 3 g of CoQ10 was dissolved was prepared. All of the above nanoemulsions were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 14: Preparation of medium- and long-chain triglyceride nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 100 grams of purified water, 100 grams of glycerol, 50 grams of xylitol, 50 grams of trehalose, 30 grams of erythritol, and 15 grams of maltodextrin were mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 170 grams of medium-chain triglycerides, 16 grams of stearic acid, 14 grams of sorbitan monostearate, 30 grams of polyethylene glycol sorbitan monostearate, and 30 grams of PEG-40 hydrogenated castor oil was mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 180 g of a w/o nanoemulsion consisting of 54 g of an aqueous phase and 120 g of an oil phase in which 6 g of lutein was dissolved was prepared.

Following the procedure described in Example 2, 300 g of an o/w nanoemulsion consisting of 174 g of an aqueous phase and 120 g of an oily phase in which 6 g of lutein was dissolved was prepared.

The nanoemulsions were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35<51>, Antimicrobial Effectiveness Testing, page 52, and both nanoemulsions prepared in this example passed the antimicrobial test.

Example 15: Preparation of CoQ10-containing medium-chain triglyceride oil nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 100 grams of purified water, 100 grams of glycerol, 50 grams of xylitol, 50 grams of trehalose, 35 grams of erythritol, and 15 grams of maltodextrin were mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 50 grams of medium-chain triglycerides, 50 grams of fish oil, 10 grams of stearic acid, 8 grams of sorbitan monostearate, 20 grams of polyethylene glycol sorbitan monostearate, and 20 grams of PEG-40 hydrogenated castor oil was mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 125 g of a w/o nanoemulsion consisting of 20 g of an aqueous phase and 100 g of an oil phase in which 5 g of CoQ10 was dissolved was prepared.

Following the procedure described in Example 2, 100 g of an o/w nanoemulsion consisting of 58 g of an aqueous phase and 40 g of an oil phase in which 2 g of CoQ10 was dissolved was prepared.

The nanoemulsions were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 16: Preparation of Squalene/Caprylic Capric Triglyceride Nanoemulsion Containing Isosorbide Dinitrate or Famotidine

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 150 grams of purified water, 150 grams of urea, and 40 grams of propylene glycol were mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 80 grams of squalene, 80 grams of caprylic capric triglyceride, 16 grams of stearic acid, 14 grams of sorbitan monostearate, 40 grams of polyoxyethylene glycol (40) stearate, and 40 grams of PEG-40 hydrogenated castor oil was mixed by constant manual stirring in a 500-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 150 g of w/o nanoemulsion consisting of 60 g of aqueous phase and 90 g of oil phase was prepared.

Following the procedure described in Example 2, 150 g of an o/w nanoemulsion consisting of 90 g of aqueous phase and 60 g of oil was prepared.

Following the procedure described in Example 2, 150 g of an o/w nanoemulsion consisting of 88.5 g of an aqueous phase and 60 g of an oily phase in which 1.5 g of isosorbide dinitrate was dissolved was prepared.

Following the procedure described in Example 2, 150 g of an o/w nanoemulsion consisting of 88.5 g of an aqueous phase and 60 g of an oily phase in which 1.5 g of famotidine was dissolved was prepared.

All the above nanoemulsions were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 17: Preparation of synthetic oil nanoemulsions containing curcumin or testosterone

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 150 grams of purified water, 150 grams of urea, and 40 grams of propylene glycol were mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 80 grams of caprylic capric triglyceride, 40 grams of ethyl oleate, 40 grams of sorbitan oleate, 8 grams of beeswax, 8 grams of lauric acid, 8 grams of sorbitan monostearate, and 64 grams of polyoxyethylene glycol (40) stearate was mixed by constant manual stirring in a 400-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 135 g of w/o nanoemulsion consisting of 45 g of aqueous phase and 90 g of oil phase was prepared.

Following the procedure described in Example 2, 135 g of a w/o nanoemulsion consisting of 45 g of an aqueous phase and 88.2 g of an oil phase in which 1.8 g of testosterone was dissolved was prepared.

135 g of w/o nanoemulsion consisting of 45 g of aqueous phase and 89.4 g of oil phase in which 0.6 g of curcumin was dissolved was prepared following the procedure described in Example 2.

All the above nanoemulsions were transparent and stable at room temperature for at least 3 months. They exhibited the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and all the nanoemulsions prepared in this example passed the antimicrobial test.

Example 18: Preparation of Nanoemulsion Containing CoQ10, Vitamin A, Vitamin E, and Vitamin D

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 280 grams of purified water, 240 grams of glycerol, 48 grams of urea, and 32 grams of trehalose were mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form a 600-gram aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 2.4 grams of CoQ10, 4.8 grams of vitamin A, 1.2 grams of vitamin D 1.2, 30 grams of vitamin E, 85.6 grams of paraffin oil, 140 grams of cyclomethicone (DC-345), 32 grams of stearic acid, 24 grams of sorbitan stearate, and 80 grams of polyethylene glycol sorbitan monostearate was mixed by constant manual stirring in a 400-ml beaker at 65° C. to 75° C. to form a 400-gram oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 1000 g of a nanoemulsion consisting of 600 g of aqueous phase and 400 g of oil phase was prepared.

The above nanoemulsion is a transparent o/w nanoemulsion and is stable at room temperature for at least 3 months. It exhibits the Tyndall light refraction effect.

The type of nanoemulsion was determined following the procedure described in Example 1.

Antimicrobial testing was performed following the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and the nanoemulsion passed this antimicrobial test.

Example 19: Preparation of Vitamin E/Grapeseed Oil/Coconut Oil/Mink Oil/Paraffin Oil/Cyclomethicone Nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 168 grams of purified water, 115 grams of urea, 77 grams of glycerol, 20 grams of propylene glycol, 20 grams of sodium pyrrolidone formate, and 20 grams of trehalose were mixed with constant manual stirring in a 500-ml beaker at 65-75°C to form 420 grams of an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 30 grams of vitamin E, 30 grams of grapeseed oil, 40 grams of coconut oil, 8 grams of mink oil, 24 grams of paraffin oil, 60 grams of cyclomethicone (DC-345), 16 grams of beeswax, 8 grams of glyceryl monostearate, 19 grams of stearic acid, 17 grams of sorbitan monostearate, 50 grams of PEG-40 hydrogenated castor oil, and 28 grams of polyoxyethylene glycol (40) stearate were mixed by constant manual stirring in a 400-ml beaker at 65° C. to 75° C. to form 330 grams of an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 750 g of a nanoemulsion consisting of 420 g of an aqueous phase and 330 g of an oil phase was prepared.

The above nanoemulsion is a transparent o/w nanoemulsion and is stable at room temperature for at least 3 months. It exhibits the Tyndall light refraction effect.

The type of nanoemulsion was determined following the procedure described in Example 1.

Antimicrobial testing was performed following the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and the nanoemulsion passed this antimicrobial test.

Example 20: Preparation of Vitamin E/Grapeseed Oil/Coconut Oil/Mink Oil/Paraffin Oil/Cyclomethicone Nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 168 grams of purified water, 115 grams of urea, 77 grams of glycerol, 20 grams of propylene glycol, 20 grams of sodium pyrrolidone formate, and 20 grams of trehalose were mixed with constant manual stirring in a 500-ml beaker at 65-75°C to form 420 grams of an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 30 grams of vitamin E, 30 grams of grapeseed oil, 40 grams of coconut oil, 8 grams of mink oil, 24 grams of paraffin oil, 60 grams of cyclomethicone (DC-345), 16 grams of beeswax, 8 grams of glyceryl monostearate, 19 grams of stearic acid, 17 grams of sorbitan monostearate, 50 grams of PEG-40 hydrogenated castor oil, and 28 grams of polyethylene glycol sorbitan monostearate were mixed by constant manual stirring in a 400-ml beaker at 65° C. to 75° C. to form 330 grams of an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 750 g of a nanoemulsion consisting of 420 g of an aqueous phase and 330 g of an oily phase was prepared.

The above nanoemulsion is a transparent o/w nanoemulsion and is stable at room temperature for at least 3 months. It exhibits the Tyndall light refraction effect.

The type of nanoemulsion was determined following the procedure described in Example 1.

Antimicrobial testing was performed following the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and the nanoemulsion passed this antimicrobial test.

Example 21: Preparation of Vitamin E/Grapeseed Oil/Coconut Oil/Mink Oil/Paraffin Oil/Cyclomethicone Nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 168 grams of purified water, 115 grams of urea, 77 grams of glycerol, 20 grams of propylene glycol, 20 grams of sodium pyrrolidone formate, and 20 grams of trehalose were mixed with constant manual stirring in a 500-ml beaker at 65-75°C to form 420 grams of an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 30 grams of vitamin E, 30 grams of grapeseed oil, 40 grams of coconut oil, 8 grams of mink oil, 24 grams of paraffin oil, 60 grams of cyclomethicone (DC-345), 16 grams of beeswax, 8 grams of glyceryl monostearate, 19 grams of stearic acid, 17 grams of sorbitan monostearate, 50 grams of PEG-40 hydrogenated castor oil, and 28 grams of polyoxyethylene sorbitan monooleate were mixed by constant manual stirring in a 400-ml beaker at 65° C. to 75° C. to form 330 grams of an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 750 g of a nanoemulsion consisting of 420 g of an aqueous phase and 330 g of an oily phase was prepared.

The above nanoemulsion is a transparent o/w nanoemulsion and is stable at room temperature for at least 3 months. It exhibits the Tyndall light refraction effect.

The type of nanoemulsion was determined following the procedure described in Example 1.

Antimicrobial testing was performed following the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and the nanoemulsion passed this antimicrobial test.

Example 22: Preparation of Vitamin E/Grapeseed Oil/Coconut Oil/Mink Oil/Paraffin Oil/Cyclomethicone Nanoemulsion

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 150 grams of purified water, 150 grams of urea, and 40 grams of propylene glycol were mixed by constant manual stirring in a beaker at 65-75°C to form 340 grams of an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 30 grams of vitamin E, 30 grams of grapeseed oil, 40 grams of coconut oil, 8 grams of mink oil, 24 grams of paraffin oil, 60 grams of cyclomethicone (DC-345), 16 grams of beeswax, 8 grams of glyceryl monostearate, 19 grams of stearic acid, 17 grams of sorbitan monostearate, 50 grams of PEG-40 hydrogenated castor oil, and 28 grams of polyoxyethylene glycol (40) stearate were mixed by constant manual stirring in a 400-ml beaker at 65° C. to 75° C. to form 330 grams of an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 750 g of a nanoemulsion consisting of 420 g of an aqueous phase and 330 g of an oily phase was prepared.

The above nanoemulsion is a transparent o/w nanoemulsion and is stable at room temperature for at least 3 months. It exhibits the Tyndall light refraction effect.

The type of nanoemulsion was determined following the procedure described in Example 1.

Antimicrobial testing was performed following the procedure described in USP 35 <51>, Antimicrobial Effectiveness Testing, page 52, and the nanoemulsion passed this antimicrobial test.

Example 23: Preparation of essential oil nanoemulsion containing only one hydrophilic surfactant

The nanoemulsions were prepared following the procedure described below.

Preparation of the aqueous phase of nanoemulsion

A combination of 200 grams of purified water, 100 grams of glycerin, 50 grams of glucosamine, and 50 grams of methylsulfonylmethane was mixed by constant manual stirring in a 500-ml beaker at 65-75°C to form an aqueous phase.

Preparation of the oil phase of nanoemulsion

A combination of 30 grams of vitamin E, 30 grams of grapeseed oil, 40 grams of coconut oil, 8 grams of mink oil, 24 grams of paraffin oil, 60 grams of cyclomethicone (DC-345), 16 grams of beeswax, 8 grams of glyceryl monostearate, 19 grams of stearic acid, 17 grams of sorbitan monostearate, and 68 grams of PEG-40 hydrogenated castor oil were mixed by constant manual stirring in a 400-ml beaker at 65° C. to 75° C. to form an oil phase.

Preparation of nanoemulsion

Following the procedure described in Example 2, 150 g of w/o nanoemulsion consisting of 60 g of aqueous phase and 90 g of oil phase was prepared.

Following the procedure described in Example 2, 150 g of an o/w nanoemulsion consisting of 90 g of an aqueous phase and 60 g of an oily phase was prepared.

The above nanoemulsion is transparent and stable at room temperature for at least 3 months. It exhibits the Tyndall light refraction effect.

The procedure described in Example 1 was followed to determine the type of each nanoemulsion prepared in this example.

The antimicrobial test was performed according to the procedure described in USP 35<51>, Antimicrobial Effectiveness Testing, page 52, and both nanoemulsions prepared in this example passed the antimicrobial test.

Other embodiments

All features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Therefore, unless expressly stated otherwise, each feature disclosed is merely one example of a series of equivalent or similar general features.

Based on the above description, those skilled in the art can easily ascertain the essential features of the present invention and, without departing from the spirit and scope of the present invention, can make various changes and modifications to the present invention to adapt it to various uses and conditions. Therefore, other embodiments are also within the scope of the following claims.

Claims (22)

1. A nanoemulsion comprising: (A) Aqueous phase, which includes: (1) Water or aqueous solution, and (2) One or more water-soluble organic nanostructure stabilizers, The water or aqueous solution contains less than 75% by weight of the aqueous phase, and the one or more water-soluble organic nanostructure stabilizers contain less than 99% by weight of the aqueous phase. The one or more water-soluble organic nanostructure stabilizers are selected from urea, erythritol, trehalose, maltodextrin, xylitol, mannitol, and glucosamine. (B) Oil phase, which includes: (1) Oil or oil solution, (2) Organic gel thickeners, and (3) A hydrophilic surfactant with a hydrophilicity-lipophilicity balance value greater than 8.0, wherein the hydrophilic surfactant is PEG-40 hydrogenated castor oil, polyethylene glycol dehydrated sorbitan monostearate, polyoxyethylene glycol (40) stearate, polyoxyethylene dehydrated sorbitan monooleate, or a mixture thereof. The oil or oil solution contains less than 80% by weight of the oil phase, the organic gel thickener contains less than 60% by weight of the oil phase, and the hydrophilic surfactant contains less than 60% by weight of the oil phase. The water or aqueous solution comprises less than 38% by weight of the nanoemulsion, the weight ratio of the aqueous phase to the oil phase is 1:40 to 100:1, the aqueous phase is dispersed in the oil phase in the form of nano-sized droplets or the oil phase is dispersed in the aqueous phase in the form of nano-sized droplets, and the nanoemulsion is self-preservative in the absence of antimicrobial preservatives and has a reversible continuous and dispersed phase. 2. The nanoemulsion of claim 1, wherein the oil phase is dispersed in the aqueous phase in the form of nanoscale droplets. 3. The nanoemulsion of claim 1, wherein the aqueous phase is dispersed in the oil phase in the form of nanoscale droplets. 4. The nanoemulsion of claim 2, wherein the hydrophilicity-lipophilicity balance value is greater than 10. 5. The nanoemulsion of claim 4, wherein the hydrophilicity-lipophilicity balance value is greater than 13. 6. The nanoemulsion of claim 3, wherein the hydrophilicity-lipophilicity balance value is greater than 10. 7. The nanoemulsion of claim 6, wherein the hydrophilicity-lipophilicity balance value is greater than 13. 8. The nanoemulsion of claim 4, wherein the oil is a vegetable oil, silicone oil, synthetic oil, mineral oil, animal oil, essential oil, or a combination thereof; and the organic gel thickener is a saturated fatty acid, fatty acid alcohol, fatty acid derivative with a melting point greater than 45°C, or a combination thereof. 9. The nanoemulsion of claim 4, wherein the oil is coconut oil, palm oil, grapeseed oil, grapefruit oil, olive oil, avocado oil, evening primrose oil, tea tree oil, eucalyptus oil, lavender oil, rosemary oil, horse fat, fish oil, squalene, lanolin oil, cyclomethicone, cyclopentasiloxane, phenyltrimethylpolysiloxane, caprylic or caprylic triglyceride, isopropyl myristate, isostearyl isostearate, decyl oleate, ethylhexyl isononanoate, isohexadecane, octyldodecyl alcohol, paraffin oil, polyisobutylene, polydecene, menthol, or a combination thereof; and the organic gel thickener is stearic acid, lauric acid, glyceryl monostearate, PEG 6000 distearate, monoglycerides, diglycerides, sugar fatty acid esters, propylene glycol fatty acid esters, glycol fatty acid esters, fatty acid hexyldecyl ester, fatty acid alcohol, hexadecyl stearate, ascorbic acid fatty acid ester, glyceryl fatty acid ester, or a combination thereof. 10. The nanoemulsion of claim 9, wherein the hydrophilicity-lipophilicity balance value is greater than 13; the content of water or aqueous solution is less than 60% by weight of the aqueous phase, and the content of water-soluble organic nanostructure stabilizer is less than 50% by weight of the aqueous phase; the content of oil or oil solution is less than 65% by weight of the oil phase, the content of organic gel thickener is less than 25% by weight of the oil phase, and the content of hydrophilic surfactant is less than 35% by weight of the oil phase; the water or aqueous solution accounts for less than 30% by weight of the nanoemulsion, and the weight ratio of the aqueous phase to the oil phase is 1:2 to 3:1; and the pH of the nanoemulsion is 3 to 11 and it is transparent or translucent. 11. The nanoemulsion of claim 6, wherein the oil is a vegetable oil, silicone oil, synthetic oil, mineral oil, animal oil, essential oil, or a combination thereof; and the organic gel thickener is a saturated fatty acid, a fatty acid alcohol, a fatty acid derivative with a melting point greater than 45°C, or a combination thereof. 12. The nanoemulsion of claim 6, wherein the oil is coconut oil, palm oil, grapeseed oil, grapefruit oil, olive oil, avocado oil, evening primrose oil, tea tree oil, eucalyptus oil, lavender oil, rosemary oil, horse fat, fish oil, squalene, lanolin oil, cyclomethicone, cyclopentasiloxane, phenyltrimethylpolysiloxane, caprylic or caprylic triglyceride, isopropyl myristate, isostearyl isostearate, decyl oleate, ethylhexyl isononanoate, isohexadecane, octyldodecyl alcohol, paraffin oil, polyisobutylene, polydecene, menthol, or a combination thereof; and the organic gel thickener is stearic acid, lauric acid, glyceryl monostearate, PEG 6000 distearate, monoglycerides, diglycerides, sugar fatty acid esters, propylene glycol fatty acid esters, glycol fatty acid esters, fatty acid hexyldecyl ester, fatty acid alcohol, hexadecyl stearate, ascorbic acid fatty acid ester, glyceryl fatty acid ester, or a combination thereof. 13. The nanoemulsion of claim 12, wherein the hydrophilicity-lipophilicity balance value is greater than 13; the content of water or aqueous solution is less than 60% by weight of the aqueous phase, and the content of the water-soluble organic nanostructure stabilizer is less than 50% by weight of the aqueous phase; the content of oil or oil solution is less than 65% by weight of the oil phase, the content of the organic gel thickener is less than 25% by weight of the oil phase, and the content of the hydrophilic surfactant is less than 35% by weight of the oil phase; the water or aqueous solution accounts for less than 30% by weight of the nanoemulsion, and the weight ratio of the aqueous phase to the oil phase is 1:2 to 3:1; and the pH of the nanoemulsion is 3 to 11 and it is transparent or translucent. 14. The nanoemulsion of claim 8, wherein the content of water or aqueous solution is less than 60% by weight of the aqueous phase, and the content of the water-soluble organic nanostructure stabilizer is less than 70% by weight of the aqueous phase; the content of oil or oil solution is 30% to 70% by weight of the oil phase, the content of the organic gel thickener is less than 45% by weight of the oil phase, and the content of the hydrophilic surfactant is less than 45% by weight of the oil phase; and the weight ratio of the aqueous phase to the oil phase is 1:3 to 4:1. 15. The nanoemulsion of claim 14, wherein the content of water or aqueous solution is less than 45% by weight of the aqueous phase, and the content of the water-soluble organic nanostructure stabilizer is less than 50% by weight of the aqueous phase; the content of oil or oil solution is 45% to 65% by weight of the oil phase, the content of the organic gel thickener is less than 25% by weight of the oil phase, and the content of the hydrophilic surfactant is less than 35% by weight of the oil phase; and the water or aqueous solution accounts for less than 30% by weight of the nanoemulsion, and the weight ratio of the aqueous phase to the oil phase is 1:2 to 3:1. 16. The nanoemulsion of claim 11, wherein the content of water or aqueous solution is less than 60% by weight of the aqueous phase, and the content of the water-soluble organic nanostructure stabilizer is less than 70% by weight of the aqueous phase; the content of oil or oil solution is 30% to 70% by weight of the oil phase, the content of the organic gel thickener is less than 45% by weight of the oil phase, and the content of the hydrophilic surfactant is less than 45% by weight of the oil phase; and the weight ratio of the aqueous phase to the oil phase is 1:3 to 4:1. 17. The nanoemulsion of claim 16, wherein the content of water or aqueous solution is less than 45% by weight of the aqueous phase, and the content of the water-soluble organic nanostructure stabilizer is less than 50% by weight of the aqueous phase; the content of oil or oil solution is 45% to 65% by weight of the oil phase, the content of the organic gel thickener is less than 25% by weight of the oil phase, and the content of the hydrophilic surfactant is less than 35% by weight of the oil phase; and the water or aqueous solution accounts for less than 30% by weight of the nanoemulsion, and the weight ratio of the aqueous phase to the oil phase is 1:2 to 3:1. 18. The nanoemulsion of claim 15, wherein the nanoemulsion has a pH of 3 to 11 and is transparent or translucent. 19. The nanoemulsion of claim 17, wherein the nanoemulsion has a pH of 3 to 11 and is transparent or translucent. 20. The nanoemulsion of claim 1, wherein the nanoemulsion has a pH of 3 to 11 and is transparent or translucent. 21. The nanoemulsion of claim 1, wherein the nanoemulsion is a cosmetic, pharmaceutical product, food, household chemical, agricultural product, printing product, dyeing product, veterinary product, or diagnostic product. 22. A method for preparing the nanoemulsion as described in claim 1, the method comprising: (1) A mixture of water or an aqueous solution with a water-soluble organic nanostructure stabilizer is formed to form an aqueous phase, wherein the content of the water or aqueous solution is less than 75% by weight of the aqueous phase, and the content of the water-soluble organic nanostructure stabilizer is less than 99% by weight of the aqueous phase. (2) An oil or oil solution, an organic thickener, and a hydrophilic surfactant with a hydrophilic-lipophilic balance value greater than 8.0 are mixed to form an oil phase, wherein the content of the oil or oil solution is less than 80% by weight of the oil phase, the content of the organic gel thickener is less than 60% by weight of the oil phase, and the content of the hydrophilic surfactant is less than 60% by weight of the oil phase; and (3) The aqueous phase and the oil phase are mixed to form a nanoemulsion, wherein the weight ratio of the aqueous phase to the oil phase is 1:40 to 100:1, and wherein the water or aqueous solution accounts for less than 38% by weight of the nanoemulsion. Thus, the aqueous phase is dispersed in the oil phase in the form of nano-sized droplets, or the oil phase is dispersed in the aqueous phase in the form of nano-sized droplets, wherein the nanoemulsion is self-preservative in the absence of antimicrobial preservatives and has a reversible continuous and dispersed phase.