CN107049805B - Sunscreen spray and preparation method thereof - Google Patents

Abstract

The invention discloses a sunscreen spray and a preparation method thereof, and the sunscreen spray comprises sunscreen components: homosalate, ethylhexyl methoxycinnamate, ethylhexyl salicylate, 4-methylbenzylidene camphor, and titanium dioxide; and polydimethylsiloxane, an emulsifier component: sodium acrylate/sodium acryloyldimethyl taurate copolymer, isohexadecane and polysorbate-80, coco glucoside and coconut alcohol, glyceryl stearate and PEG-100 stearate, and other additives such as propylene glycol and magnesium aluminum silicate. The sunscreen spray disclosed by the invention is low in viscosity, stable in product system, lasting and constant in SPF value, good in air permeability after spraying, compact in film forming and capable of realizing excellent water resistance, so that a long-term sunscreen effect is achieved.

Description

Sunscreen spray and preparation method thereof

Technical Field

The invention relates to a sunscreen spray and a preparation method thereof, belonging to the technical field of cosmetics.

Background

With the improvement of people's awareness of sun protection, sun protection products are more and more concerned by people, and the market of sun protection products is also larger and larger. For sunscreen, the reaction and synergistic effect between raw materials is helpful for developing safe and effective sunscreen products meeting the continuous change in the industry, and is of great importance in excellent stability, mildness, unique skin feel, high SPF, all-band sunscreen, good waterproof performance, easy use and the like.

Sun protection to achieve high SPF cut full band sun protection, it is conventional practice to add high doses of sunscreen, but this can result in poor stability or spreadability of the material. Formulations with higher levels of emulsifier, low viscosity, stable sprays, while reducing the heavy skin feel associated with organic sunscreen levels, the use of high levels of emulsifier may also lead to skin irritation and problems with penetration of sunscreen into the skin. Most sunscreen sprays are in the form of aerosol pressure tanks, and are one-component type and two-component type, and a part of volatile gas is filled to assist spraying. The sun-proof emulsion is also thin, is directly sprayed out by a spray head, and is characterized by being more quickly coated when being used in a large area and bringing a cool feeling. However, sunscreen emulsions do not apply well as sunscreen sprays, which typically require a propellant gas. .

Disclosure of Invention

The object of the present invention is to provide a sunscreen spray which is system stable, mild, high SPF and UVA.

The invention also aims to provide a preparation method of the sunscreen spray.

The invention adopts the following scheme:

the sunscreen spray is characterized by comprising the following components in percentage by mass:

phase A: sunscreen component

6 to 10 percent of homosalate

5-9% of ethylhexyl methoxycinnamate

2 to 6 percent of ethylhexyl salicylate

2-5% of 4-methylbenzylidene camphor

2 to 6 percent of titanium dioxide

Phase B: 3-8% of polydimethylsiloxane

And C phase: emulsifier component

10.6 to 1.2 percent of emulsifier

20.6 to 1.2 percent of emulsifier

20.6 to 2.0 percent of emulsifier

Phase D: other Components

3-6% of propylene glycol

0.2 to 0.8 percent of aluminum magnesium silicate

0.3-0.6% of safflower extract

0.05-0.3% of sunflower seed extract

0.1 to 0.4 percent of triethanolamine

0.05 to 0.3 percent of allantoin

0.01 to 0.1 percent of EDTA disodium

Balance of deionized water

Phase E: 0.6 to 1.0 percent of preservative and essence.

The emulsifier 1 in the invention is composed of sodium acrylate/sodium acryloyldimethyl taurate copolymer, isohexadecane and polysorbate-80; emulsifier 2 is composed of coco glucoside and coco alcohol; emulsifier 3 consists of glyceryl stearate and PEG-100 stearate.

The preservative in the invention comprises phenoxyethanol, ethylhexyl glycerol, methylparaben and ethylparaben.

The magnesium aluminum silicate (VEEGUM) in the invention is natural smectite which is washed by water to ensure that the purity and the characteristics are as good as possible. Smectites are valuable because of their swelling capacity in water and the ability to bring beneficial rheological properties to aqueous systems, VEEGUM is used to stabilize suspensions, make emulsified systems more performing and give the product optimum fluidity.

VEEGUM, a high purity smectite, acts as a stabilizer and a rheological agent due to their specific colloidal structure in water. Each smectite particle consists of a small piece that is also difficult to observe under a microscope in tens of millions. The pieces are stacked together in a "sandwich" configuration with a layer of water between each two pieces (see FIG. 1). The surface of these platelets is negatively charged, while their edges are partially positively charged, and the net negative charge on the platelets is largely neutralized by sodium ions, although minor amounts of other inorganic cations are also present in the system. These inorganic cations associated with the platelet surface in a charge balance state are referred to as "exchangeable ions" because they are easily replaced by other cations (as shown in fig. 2).

When the smectite and water are mixed, the latter penetrates the area between the platelets, forcing the platelets further apart. In this manner, the exchangeable ions begin to diffuse away from the surface of the chip. According to the principle of osmosis, water molecules penetrate further between the platelets until the platelets are completely separated, a process known as hydration. Before hydration, as shown in figure 3, and after hydration, as shown in figure 4.

For most smectites, the rate of platelet separation is directly related to the energy involved in hydration. Not only mechanical energy but also thermal energy promotes hydration: high shear mixing or the use of warm water will reduce the time to hydration. If other substances to be dissolved are present in the water, this will lead to an extended hydration time due to the obstruction of the penetration and swelling which is important for the separation of the platelets.

The rheological properties (rheology) of VEEGUM, once the smectite is hydrated (i.e. the platelets are separated), the weakly positively charged platelet edges are attracted to the negatively charged platelet surface. This rapidly establishes a three-dimensional structure (known as the "card of Cards") (see FIG. 5), which rapidly increases the viscosity of the system. After some time, the free platelets that remain without being attracted to an opposite charge take longer to find the proper alignment in the structure, so that the increase in viscosity must be slowed down gradually, and conversely, when a shear force is applied, most of the structure collapses rapidly, and then gradually relaxes. Thus, the dispersion of smectite is thixotropic: i.e., without shear, their viscosity increases with time, while at a constant shear rate, their viscosity decreases with time. Dispersions of smectite are pseudoplastic in nature because an increase in shear rate (i.e., an increase in structural failure) results in a decrease in viscosity. Applying shear forces of different magnitudes will result in different viscosities.

The structure of the VEEGUM colloid in water also gives the smectite many useful properties-yield value. This is a measure of the ability of the colloidal structure to resist damage. To collapse such a structure, the minimum force that must be applied is the yield value. Solids, oils and various gases are surrounded and separated by this structure. They must be forced to a force greater than the yield value to pass through the liquid. This means that the greater the yield value, the more stable the suspension, emulsion or foam.

A unique and valuable property of VEEGUMs is their ability to deliver a yield value at low viscosities. Stabilization of the dispersed phase is possible even in thin fluids for which flowability is important. Most common organic thickeners have little or no yield value and are only capable of stabilizing suspensions, emulsions or foams at high viscosities.

VEEGUM imparts good properties to the formulation.

Stabilizing the emulsion: one of the most useful properties of VEEGUM is that they stabilize oil-in-water emulsions (O/W) at low concentrations. The colloidal structure of the smectite effectively suspends and disperses the droplets of the internal phase (oil phase). Because the viscosity of the smectite is not affected by heat, VEEGUM has a reduced tendency to thin and break the emulsion at elevated temperatures. Small amounts of VEEGUM will stabilize emulsions containing a wide variety of oils, fats and waxes together and containing anionic or nonionic surfactants.

Furthermore, VEEGUM has been found to be an effective stabilizer for water-in-oil (w/o) emulsions, and increasing the viscosity of the internal phase prevents coalescence. Some migration of the smectite may occur, which enhances the water/oil interfacial film. VEEGUM has been used in the formulation of water-in-oil (w/o) emulsions, otherwise it is difficult to stabilize such systems.

Stabilizing the suspension: like its stability in emulsified systems, the colloidal structure of VEEGUM also provides optimal suspensibility for fine particles in aqueous systems.

VEEGUM as suspending agent has many advantages, they can:

1. preventing forced accumulation of suspended matter.

2. The bleeding phenomenon (gel shrinkage) is controlled, making the suspension, which tends to be dense, easily redispersible.

3. Ensure the homogeneity of the product of the formulation, especially cosmetic suspensions and concentrates of pharmaceutical products.

4. Can suspend to the maximum extent without losing the pourability.

5. No jelly-like irreversible gels are formed, whereas many organic gels are formed.

6. At equivalent viscosities, better suspension efficiency than organic gums is exhibited, which is particularly useful at low viscosities.

VEEGUM can change rheological property and control thixotropy, and shear thinning products can be prepared according to formula. Thick creams can also be applied smoothly. Spraying is easier, evenly applied and adheres to vertical surfaces. The suspension was pumped and poured freely without affecting its stability.

Improving skin feel: VEEGUM brings about good spreadability and cosmetic elegance to the relevant products. Because of its insolubility and thin application properties in aqueous suspension, it is commonly used to formulate products requiring non-sticky skin feel. It is also commonly used to reduce or eliminate the sticky, gummy or stringiness properties of organic gums and polymers.

Coco glucoside/cocool (MONTANOV S) is a glucoside emulsifier that is derived entirely from plant-derived materials. The glycosidic bond between the hydrophilic part and the lipophilic fatty chain endows the molecule with perfect stability and excellent hydrolysis resistance, and is a co-emulsifier capable of improving the fluidity of the emulsion. It can provide the emulsion with smooth texture for a long time and can meet various requirements of the formula of the sunscreen product, and the molecular formula of the coco glucoside is as follows:

the compound MONTANOV S of the invention can keep the smooth texture of the emulsion for a long time, and the dispersion of the chemical sunscreen agent and the physical sunscreen agent is stable and uniform for a long time, so that the SPF value of the product is kept constant after the product is stored for one year.

The MONTANOV S can ensure that the micro titanium dioxide (titanium dioxide, with the average grain diameter of 20 multiplied by 100nm, wrapped by dimethyl silicon oil) has excellent dispersibility. Microscopic observation shows that the titanium dioxide in the emulsion containing MONTANOV S is uniformly dispersed and kept constant for a long time. In conventional emulsifier systems, they stick together and form clumps of various sizes in the emulsion.

A method of making a sunscreen spray as claimed in claim 1 comprising the steps of:

a. heating the phase C to 80-85 ℃, preserving the temperature to 75 ℃, adding the phase A and the phase B, and uniformly stirring to form a mixed phase;

b. heating the phase D to 80-85 ℃, keeping the temperature to 75 ℃, and uniformly stirring;

c. pumping the mixed phase into a vacuum emulsifying pot, slowly pumping the mixed phase D, homogenizing for 5-10 min, keeping the temperature, stirring for 10min, and vacuumizing for cooling;

d. cooling to 60 ℃, homogenizing for 2-3 min, continuing vacuumizing and cooling, and uniformly stirring;

e. and (5) adding the phase E when the temperature is reduced to 40 ℃, uniformly stirring, and discharging after the inspection is qualified.

Compared with the existing products, the invention has the following advantages:

the invention uses coco glucoside/coconut alcohol combination emulsifier MONTANOV S and aluminum magnesium silicate thickener to make low viscosity sunscreen spray. The product of the invention has stable system, lasting and constant SPF value, good air permeability after spraying, compact film forming and excellent water resistance, thereby achieving long-term sun-proof effect.

[ description of the drawings ]

FIG. 1 is a patch diagram of smectite particles;

FIG. 2 is a schematic representation of the other substitution of cations in smectite particles;

FIG. 3 is a schematic representation of the smectite particles after complete separation of the platelets;

FIG. 4 is a structural diagram of the complete penetration of water molecules into the smectite particles;

fig. 5 is a three-dimensional structure built up by the sheet-like structure after hydration of the smectite particles.

[ detailed description ] embodiments

The invention is further described below with reference to specific examples:

table 1: each component of examples 1 to 3 was contained in percentage by mass

Examples 1-3 were tested and the results are shown in Table 2:

table 2:

in examples 1-3, example 3 passed the test and at a moderate viscosity, no propellant was required, the spray was effective and the body was stable.

The MONTANOV S can ensure that the micro titanium dioxide (titanium dioxide, with the average grain diameter of 20 multiplied by 100nm, wrapped by dimethyl silicon oil) has excellent dispersibility. Microscopic observation shows that the titanium dioxide in the emulsion containing MONTANOV S is uniformly dispersed and kept constant for a long time (three years of cosmetic shelf life). In conventional emulsifier systems, they stick together and form clumps of various sizes in the emulsion.

After the in vitro SPF value of the composition in example 3 is stored for one year, the SPF value is within +/-2%, and from the experimental result, the composition of the plant-derived emulsifier coco glucoside, the cocol alcohol and the aluminum magnesium silicate can provide an efficient and stable sunscreen formula. Thus, low viscosity emulsions can be formulated as sunscreen sprays. A small amount of emulsifier is used to compound a small amount of thickener to prepare the sunscreen spray which is mild, stable and light in skin feel.

Claims (3)

1. The sunscreen spray is characterized by comprising the following components in percentage by mass:

phase A: sunscreen component

Phase B: 3-8% of polydimethylsiloxane

And C phase: emulsifier component

10.6 to 1.2 percent of emulsifier

20.6 to 1.2 percent of emulsifier

30.6 to 2.0 percent of emulsifier

Phase D: other Components

Phase E: 0.6-1.0% of preservative and essence;

the emulsifier 1 consists of a sodium acrylate/sodium acryloyldimethyl taurate copolymer, isohexadecane and polysorbate-80;

the emulsifier 2 consists of coco glucoside and coco alcohol;

the emulsifier 3 is composed of glycerol stearate and PEG-100 stearate.

2. The sunscreen spray of claim 1, wherein the preservatives comprise phenoxyethanol, ethylhexyl glycerin, methylparaben, and ethylparaben.

3. A process for the preparation of a sunscreen spray according to claim 1 or 2, characterized in that it comprises the following steps:

a. heating the phase C to 80-85 ℃, preserving the temperature to 75 ℃, adding the phase A and the phase B, and uniformly stirring to form a mixed phase;

b. heating the phase D to 80-85 ℃, keeping the temperature to 75 ℃, and uniformly stirring;

c. pumping the mixed phase into a vacuum emulsifying pot, slowly pumping the mixed phase D, homogenizing for 5-10 min, keeping the temperature, stirring for 10min, and vacuumizing for cooling;

d. cooling to 60 ℃, homogenizing for 2-3 min, continuing vacuumizing and cooling, and uniformly stirring;

e. and (5) adding the phase E when the temperature is reduced to 40 ℃, uniformly stirring, and discharging after the inspection is qualified.

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