A w / o / w gel type cream and a method for preparing the same

Abstract

This invention relates to a W / O / W gel-type cream and its preparation method, belonging to the technical field of pharmaceuticals and cosmetics. The W / O / W gel-type cream comprises the following components: a nonionic surfactant, an emulsifier, a gel matrix material, an oil-soluble matrix, a water-soluble matrix, a pH adjuster, and water. The pH adjuster adjusts the pH value of the W / O / W gel-type cream to 2.8–5.0. The cream of this invention exhibits good stability, remaining intact after two months at 4°C and after centrifugation (4000 r / min) for 30 minutes. Furthermore, this invention is convenient to use, with a pH of 3.5–4.5, suitable for the acidic internal environment of the human body, and possesses lubricating properties, making it suitable for long-term daily use.

Description

Technical Field

[0001] This invention relates to a method for preparing a pH-acidic, bioadhesive, and moisturizing / lubricating W / O / W gel-type cream, belonging to the field of pharmaceutical and cosmetic technology. Background Technology

[0002] W / O / W creams are complex cream systems where the dispersed phase droplets contain even smaller droplets. From the inside out, they consist of an inner aqueous phase, an inner water-oil interface film, an oil phase, an outer oil-water interface film, and an outer aqueous phase, classifying them as multiphase systems. W / O / W gel creams using a gel matrix material as the continuous phase have a high viscosity in the outer aqueous phase, making the dispersed phase more stable. The fine W / O droplets distributed within the gel are more easily absorbed by the body. Selecting a suitable gel matrix material can make the product pH-acidic, more suitable for the acidic environment of the human body (such as the vagina). The oil-soluble matrix in the system provides good lubrication, and the oil-soluble matrix, encapsulated in the inner aqueous phase, increases the surface area of ​​the oil-soluble matrix, resulting in a lubricating yet non-greasy effect. The addition of a water-soluble matrix to the inner aqueous phase provides water retention, enhancing the product's moisturizing effect. Currently, there are no research reports on W / O / W gel creams in modern technology. Summary of the Invention

[0003] In view of this, the present invention aims to provide a W / O / W gel-type cream and its preparation method.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A W / O / W gel cream comprises the following components: a nonionic surfactant, an emulsifier, a gel matrix material, an oil-soluble matrix, a water-soluble matrix, a pH adjuster, and water, wherein the pH adjuster adjusts the pH of the W / O / W gel cream to 2.8–5.0.

[0006] Preferably, the nonionic surfactant includes at least one of Span 60 or Span 40;

[0007] Preferably, the emulsifier is a fatty acid glyceride emulsifier; more preferably, the emulsifier is a mixed fatty acid glyceride.

[0008] The nonionic surfactant and the emulsifier constitute a water-in-oil emulsifier;

[0009] Preferably, the gel matrix material is carbomer;

[0010] Preferably, the oil-soluble matrix includes at least one of liquid paraffin and dimethicone; more preferably, the liquid paraffin is a light liquid paraffin.

[0011] Preferably, the water-soluble matrix includes at least one of glycerol and propylene glycol;

[0012] Preferably, the pH adjuster includes at least one of sodium hydroxide and triethanolamine;

[0013] Preferably, the W / O / W gel cream further includes a preservative; more preferably, the preservative is sorbic acid.

[0014] Preferably, the nonionic surfactant accounts for 1.5 to 3% of the total weight of the cream;

[0015] Preferably, the emulsifier accounts for 0.5% to 1% of the total weight of the cream;

[0016] More preferably, the water-in-oil emulsifier accounts for 2.0 to 4.0% of the total weight of the cream;

[0017] Preferably, the gel matrix material accounts for 1.0 to 4.0% of the total weight of the cream;

[0018] Preferably, the oil-soluble matrix accounts for 5.0 to 10.0% of the total weight of the cream;

[0019] Preferably, the water-soluble matrix accounts for 1.0 to 4.0% of the total weight of the cream;

[0020] Preferably, the preservative accounts for 0.07 to 0.2% of the total weight of the cream;

[0021] This invention also relates to a method for preparing the aforementioned W / O / W gel-type cream, the method comprising the following steps:

[0022] (1) Weigh the raw materials, including nonionic surfactants, emulsifiers, gel matrix materials, oil-soluble matrix, water-soluble matrix, pH adjuster and water;

[0023] (2) Mix the oil-soluble matrix, nonionic surfactant and emulsifier at 70-80°C, then add the water-soluble matrix and water at 70-80°C, and stir at 300-400 r / min for 25-45 minutes to obtain W / O type primary emulsion.

[0024] (3) Add the gel matrix material to water and stir at 500-600 r / min for 35-55 minutes to obtain the external aqueous phase; add the W / O pre-emulsion obtained in step (2) to the external aqueous phase at room temperature, add the pH adjuster, and stir at 400-500 r / min for 20-30 minutes to obtain the W / O / W gel cream.

[0025] In another embodiment, in step (3), a preservative is added at the same time as the pH adjuster.

[0026] In this invention, W / O refers to water-in-oil cream; O / W refers to oil-in-water cream; and W / O / W refers to water-oil-water cream.

[0027] This invention provides a W / O / W gel-type cream and its preparation method. The invention prepares the gel-type cream using a two-step emulsification method. During the preparation process, by rationally selecting the types and amounts of materials, the HLB value, viscosity, and pH value of the prepared cream can be ultimately controlled, resulting in improved yield and stability of the final cream system. It does not separate into layers after centrifugation at 4000 r / min for 30 min, and its pH value is 2.8–5.0, making it suitable for the acidic environment of the human body. Specifically, in the first emulsification step, the nonionic surfactant and the emulsifier are used as water-in-oil emulsifiers, which reduces the droplet size in the W / O emulsion prepared in the first step, improving the stability of the W / O emulsion. In the second emulsification step, a gel with the function of an oil-in-water emulsifier is formed. The formed gel has high viscosity and an acidic pH value, improving the stability of the cream while adapting to the acidic environment of the human body, allowing it to adhere to the inner wall for convenient daily use. The resulting W / O / W gel-type cream utilizes an oil-soluble base, enabling it to provide both moisturizing and lubricating effects. The preparation method for this W / O / W gel-type cream is simple, low-cost, and suitable for large-scale production. Attached Figure Description

[0028] Figure 1 The W / O / W gel-type cream obtained in Example 3 is placed in an inverted beaker.

[0029] Figure 2 The pH test results for the W / O / W gel creams obtained in Examples 1-3 are shown (from left to right: Examples 1-3).

[0030] Figure 3 The images show the microstructures of the W / O / W gel-type creams obtained in Examples 1-3 and Comparative Examples 1-5 (the first row of images, from left to right, shows Examples 1-3 and Comparative Example 1; the second row of images, from left to right, shows Comparative Examples 2-5).

[0031] Figure 4 The image shows the moisturizing test results of the W / O / W gel-type cream obtained in Example 3 (left image: before use; right image: after use). Detailed Implementation

[0032] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0033] Example 1

[0034] A w / o / w gel-type cream, by weight percentage, comprises the following ingredients: 1.5% Span 60, 0.5% mixed fatty acid glycerides, 1.0% carbomer, 10% light liquid paraffin, 1.0% glycerin, appropriate amount of sodium hydroxide, and the balance being water.

[0035] (1) Based on the weight percentage of each component in the above W / O / W gel cream, weigh out Span 60, mixed fatty acid glycerides, carbomer, light liquid paraffin, glycerin, sodium hydroxide and water;

[0036] (2) Light liquid paraffin, Span 60 and mixed fatty acid glycerides are mixed at 70°C, and then glycerol and water at 70°C are added. Stir at 400r / min for 25 minutes to obtain W / O type colostrum.

[0037] (3) Add carbomer to water and stir at 500 r / min for 55 minutes to obtain an external aqueous phase; add the W / O pre-emulsion obtained in step (2) to the external aqueous phase at room temperature, adjust the pH value to 5 with sodium hydroxide, and stir at 500 r / min for 20 minutes to obtain a W / O / W gel cream.

[0038] Example 2

[0039] A W / O / W gel-type cream, by weight percentage, comprises the following ingredients: 403% Span, 1% mixed fatty acid glycerides, 4.0% carbomer, 5% liquid paraffin, 4.0% propylene glycol, 0.2% sorbic acid, appropriate amount of triethanolamine, and the balance being water;

[0040] (1) Based on the weight percentage of each component in the above W / O / W gel cream, weigh out Span 40 and mix it with fatty acid glycerides, carbomer, liquid paraffin, propylene glycol, sorbic acid, triethanolamine and water.

[0041] (2) Mix liquid paraffin, Span 40 and mixed fatty acid glycerides at 80°C, then add propylene glycol and water at 80°C, and stir at 300 r / min for 25 minutes to obtain W / O type colostrum.

[0042] (3) Add carbomer to water and stir at 600 r / min for 35 minutes to obtain an external aqueous phase; add the W / O colostrum obtained in step (2) to the external aqueous phase at room temperature, add sorbic acid, adjust the pH value to 2.8 with triethanolamine, and stir at 400 r / min for 30 minutes to obtain a W / O / W gel cream.

[0043] Example 3

[0044] A W / O / W gel-type cream, by weight percentage, comprises the following ingredients: 2.2% Span 60, 0.8% mixed fatty acid glycerides, 2.5% carbomer, 8% dimethicone, 2.5% glycerin, 0.07% sorbic acid, appropriate amount of sodium hydroxide, and the balance being water;

[0045] (1) Based on the weight percentage of each component in the above W / O / W gel cream, weigh out Span 60 and mix it with fatty acid glycerides, carbomer, dimethicone, glycerin, sorbic acid, sodium hydroxide and water;

[0046] (2) Mix dimethicone, Span 60 2.2% and mixed fatty acid glycerides 0.8% at 75°C, then add glycerol and water at 75°C and stir at 350 r / min for 35 minutes to obtain W / O type colostrum;

[0047] (3) Add carbomer to water and stir at 550 r / min for 45 minutes to obtain an external aqueous phase; add the W / O colostrum obtained in step (2) to the external aqueous phase at room temperature, add sorbic acid, adjust the pH value to 3.6 with sodium hydroxide, and stir at 450 r / min for 25 minutes to obtain a W / O / W gel cream.

[0048] Comparative Example 1

[0049] The difference from Example 3 is that Span 60 is not used.

[0050] Comparative Example 2

[0051] The difference from Example 3 is that polyacrylic acid resin is used instead of carbomer.

[0052] Comparative Example 3

[0053] The difference from Example 3 is that sodium carboxymethyl cellulose is used instead of carbomer.

[0054] Comparative Example 4

[0055] The difference from Example 3 is that lanolin is used instead of dimethicone.

[0056] Comparative Example 5

[0057] The difference from Example 3 is that stearic acid is used instead of dimethicone.

[0058] Example 4

[0059] Stability determination

[0060] The W / O / W gel-type creams from Examples 1-3 and Comparative Examples 1-5 were simultaneously centrifuged at 4000 rpm / min for 30 min. The layering of each gel-type emulsion was observed to evaluate the stability of the gel-type creams. The mass of each gel-type cream before centrifugation was recorded as m0. After centrifugation, the supernatant was discarded, and the remaining mass was recorded as m. t mass fraction m t / m0 represents the relative mass of the gel-type cream at that moment. The larger the mass fraction, the more stable the gel-type cream prepared under those conditions. The stability (centrifugation) test results of the W / O / W gel-type creams in Examples 1-3 and Comparative Examples 1-5 are shown in Table 1.

[0061] Table 1. Stability (Centrifugation) Evaluation Results

[0062]

[0063] Comparison Table 1 shows that the W / O / W gel creams in Examples 1-3 have better stability, while the W / O / W gel creams in Comparative Examples 1-3 have poorer stability. Since stability is related to the properties and dosage of the surfactant and the preparation method of the gel cream, in Examples 1-3, the use of Span 60 or Span 40 in combination with mixed fatty acid glycerides, and adjusting the pH to 2.8-5.0 with the prescribed amount of carbomer, resulted in a W / O / W gel cream with higher stability through a two-step emulsification method. This preparation method is simple and reproducible. While Comparative Examples 4 and 5 are stable, they have a grainy feel when applied to the skin, resulting in a poorer user experience compared to Examples 1-3.

[0064] The W / O / W gel-type creams from Examples 1 to 3 were stored at 4°C, 25°C, and 60°C for one month, respectively. The stratification of each gel-type emulsion was observed to evaluate the stability of the gel-type creams. The mass of each gel-type cream on day 0 was recorded as M0. After one month, each gel-type cream was removed, the supernatant was discarded, and the remaining mass was recorded as M. t mass fraction M t / M0 represents the relative mass of the gel-type cream at that moment. The larger the mass fraction, the more stable the gel-type cream prepared under those conditions. The stability (temperature) test results of the W / O / W gel-type creams in Examples 1 to 3 are shown in Table 2.

[0065] Table 2. Stability (Temperature) Evaluation Results

[0066]

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A W / O / W gel-type cream, characterized in that, The product comprises the following components: a nonionic surfactant, an emulsifier, a gel matrix material, an oil-soluble matrix, a water-soluble matrix, a pH adjuster, a preservative, and water. The pH adjuster adjusts the pH of the W / O / W gel cream to 2.8–5.

0. The nonionic surfactant is at least one of Span 60 or Span 40, and comprises 1.5–3% of the total weight of the cream. The gel matrix material is carbomer, comprising 1.0–4.0% of the total weight of the cream. The oil-soluble matrix is ​​at least one of liquid paraffin or dimethicone, comprising 5.0–10.0% of the total weight of the cream. The emulsifier is a mixture of fatty acid glycerides, comprising 0.5–1% of the total weight of the cream. The water-soluble matrix is ​​at least one of glycerol or propylene glycol, comprising 1.0–5.0% of the total weight of the cream. 4.0%; the preservative accounts for 0.07 to 0.2% of the total weight of the cream.

2. The W / O / W gel-type cream as described in claim 1, characterized in that: The liquid paraffin is a lightweight liquid paraffin.

3. The W / O / W gel-type cream as described in claim 1 or 2, characterized in that: The pH adjuster includes at least one of sodium hydroxide and triethanolamine.

4. The W / O / W gel-type cream as described in claim 1 or 2, characterized in that, The preservative is sorbic acid.

5. The method for preparing a W / O / W gel-type cream as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Weigh the raw materials, including the nonionic surfactant, emulsifier, gel matrix material, oil-soluble matrix, water-soluble matrix, pH adjuster, preservative and water; (2) The oil-soluble matrix, nonionic surfactant and emulsifier are mixed at 70-80°C, and then the water-soluble matrix and water at 70-80°C are added. The mixture is stirred at 300-400 r / min for 25-45 minutes to obtain a W / O type primary emulsion. (3) Add the gel matrix material to water and stir at 500-600 r / min for 35-55 minutes to obtain an external aqueous phase; add the W / O pre-emulsion obtained in step (2) to the external aqueous phase at room temperature, and then add the pH adjuster and preservative, and stir at 400-500 r / min for 20-30 minutes to obtain a W / O / W gel cream.

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