Skin care creams are a class of emulsified products, which are stable mixtures of two immiscible phases (water phase and oil phase) that are dispersed in one phase as droplets or other forms in the other phase through an emulsification system.
An emulsion with an outer phase of “water” and an inner phase of “oil” is called an oil-in-water emulsion (O/W); the opposite is true for an oil-in-water emulsion (W/O) ❶.
It is a solid or semi-solid with high viscosity, unlike emulsions (which are fluid). Depending on the concentration of the two phases in the system, it has different states of appearance, cream (soft texture) and paste (hard texture).
Creams are the primary skin care product in the cosmetic product line, so to speak. Creams were the most familiar, most common and most popular products in the earliest days.
Example: Snow cream, white appearance like snowflakes, it is formulated using a soap-based reactive emulsification method and obtained, after application, can form a film on the surface of the skin, can inhibit the evaporation of epidermal moisture, not greasy very soothing, smooth, fresh and pleasant aroma gives a pleasant mood, soft skin, improve the rough and dry skin.The cream is rich in high oil, nourishing and moisturizing, which is very suitable for use in the dry autumn and winter seasons.
Classification and general composition of creams
1 . Classification of creams.
- Cold frost
- Cleansing Cream
- Snow Cream
- Massage Cream
2 . General composition of creams.
- Emulsifier (stabilizer): O/W type emulsifier (HLB 8-18), W/O type emulsifier (HLB 3-6)
- Grease: softener, moisturizer, humectant, skin feel regulator (silicone oil)
- Humectant: Moisture-absorbing agent
- Thickening agent
- Efficacy ingredients: sunscreen, anti-aging agents, etc.
Common raw materials for cream cosmetics
Emulsifier is an important component of cream formulations, which affects the final appearance of the product, stability, physical and chemical indicators. There are many types of emulsifiers, according to whether ionized in water is divided into non-ionic emulsifiers and ionic emulsifiers. We commonly used are.
- Fatty alcohol polyoxyethylene ether series, for example: stearyl polyether-21, lauryl polyether-4, cetyl stearyl polyether-12, etc..
- Polyol lipid series, such as: glyceryl stearate, PEG-20 glyceryl stearate, polyglyceryl-3 stearate, etc..
- Alkyl glycosides series, e.g. cetyl stearyl glucoside/cetyl stearyl alcohol, C14-22 alcohol/C12-20 alkyl glucoside, coconut oil based glucoside/coconut oil alcohol, etc.
- Spacer series, for example: Spacer-20 (SP-20), Spacer-80 (SP-80), etc..
- Tween series, for example: Tween 20 (TWEEN-20), Tween 40 (TWEEN-40), Tween 60 (TWEEN-60), Tween 80 (TWEEN-80), etc.
Oil has an important role in creams and creams as the main emollient that moisturizes the skin, softens it and restores its smoothness and elasticity.
The oils and fats required for creams can be divided into the following categories according to their sources: vegetable oils and fats, animal oils and fats, mineral oils and fats, and synthetic oils and fats. Among them, vegetable oils and animal fats are natural oils and fats.
Natural oils (such as: grape seed oil, jojoba oil, shea butter and beeswax, lanolin, squalane) have good compatibility with human skin, high nutritional value, easily absorbed by the skin, can moisturize the skin, make the skin soft, prevent the skin moisture evaporation, long-term moisturizing.
However, the disadvantage is that it is easy to be oxidized and rancid, and the oxidized oil itself will taste worse and discolor, which increases the irritation of the product itself. So generally want to solve this problem, consider the long-term stability of the product, you can consider adding antioxidants.
Mineral grease is petroleum-derived, compared to natural grease is greasy, poor breathability, poor skin-friendly, can not be absorbed by the skin. But its price is cheap, not easy to oxidation rancidity, good stability, good closure, inhibit skin moisture volatilization, greatly improve the skin moisturizing effect. Commonly used mineral oil are: liquid paraffin, petroleum jelly, microcrystalline paraffin, etc.
Synthetic fats and oils are generally saturated fats and oils, which are now increasingly used in cosmetics as emollients and penetration aids in creams and creams, with good stability and a refreshing and thick skin feel. We commonly use: diisostearyl malate, caprylic/capric triglyceride, isonononyl isononanoate, etc.
Silicone oil is widely used and has existed for many years in individual photos that cosmetics such as shampoo and hair care, skin care and color cosmetics.
It is breathable and stable, and in cream products, it makes the skin smooth, reduces the greasy feeling from other oils, and keeps the skin feeling soft and moisturized at all times.We commonly use: polydimethylsiloxane, silicone elastomers, cyclopentamethylsiloxane, etc.
Moisturizers are moisture-absorbing and compounds that reduce the rate of water loss from the skin’s stratum corneum, allowing the skin to achieve a long-lasting moisturizing effect.
There is a wide variety of moisturizing agents, both natural and synthetic. Moisturizers include polyols (e.g., glycerin, propylene glycol), amino acids (e.g., betaine), polysaccharides (e.g., mannitol), organic salts (e.g., PCA-sodium), etc. To briefly mention a few examples.
Hyaluronic acid is recognized as a natural moisturizing factor with strong hygroscopicity and film-forming properties.
Glycerol is a colorless. It is an odorless transparent viscous liquid with hygroscopic properties because it contains three hydroxyl groups in its molecular formula, which can form hydrogen bonds with water molecules, and can form a film on the skin to isolate water from evaporating.
But adding too much glycerin can be irritating. In addition to absorbing moisture from the air, high concentrations of glycerin will also draw moisture from the skin’s stratum corneum, so the skin will become dry, so be moderate in the amount of glycerin.
Thickener is a rheological additive, with a variety of functions such as thickening, suspension, emulsification and stabilization.There are also a great variety of them, and we commonly see.
1 Organic natural thickeners, e.g. hyaluronic acid, xanthan gum, micronucleus gum, etc..
2 organic semi-synthetic thickeners, for example: sodium carboxymethyl cellulose, hydroxyethyl cellulose, etc..
3 Organic synthetic thickeners, e.g. carbomer, acrylic (ester)/C10-30 alkyl acrylate crosspolymer, ammonium acryloyldimethyl taurate/VP copolymer, sodium polyacrylate, polyethylene glycol, etc..
4 micronized thickening agent, for example: aluminum magnesium sulfate, silica, bentonite, etc.
Classification and general composition of creams
Creams and cosmetics are rich in many nutrients, and after contamination by microorganisms the product itself will undergo qualitative changes, such as: odor, discoloration, physical and chemical indicators beyond the prescribed range (pH changes), emulsion breaking, caking, and a series of problems.To prevent these problems from occurring and to extend the life of the product, it is necessary to add a preservative.
The choice of preservative must be safe, non-irritating, antimicrobial, stable and well-matched. Of course the basis for preservatives to achieve these is to be within the range of permitted preservatives listed in the 2015 edition of the Technical Specification for Cosmetic Safety. Commonly used preservatives are: phenoxyethanol, DMDM acetonitrile, nipagin ester, etc.
The amount of flavoring in the product is very small, and is a trace ingredient, but it is this minuscule amount that determines how good or bad the first impression of the product is to the customer after the product is launched.
Therefore, it plays an important role in the formulation of creams, not only to mask the odor of the raw material itself, but also to bring a fresh and pleasant fragrance, giving a pleasant feeling.
As society continues to pursue health and safety and improve the safety of cosmetics, companies are beginning to work on natural fragrance oils, such as: lavender oil, rose oil, scented geranium (PELARGONIUM GRAVEOLENS) oil, and so on.
Cream production process and FAQ
Process quality control.
1 O/W grease temperature shall not exceed 85℃, natural grease temperature moderately lower (easy to oxidize), heating time should not be too long to prevent the dissipation of volatile grease.
2 Thickener dispersion to be uniform.
3 Dissolution and temperature of the aqueous phase.
4 water-oil phase mixing, high temperature when the opening of high homogenization efforts more conducive to stability.
5 W/O type products are water phase added to the oil phase, the temperature should not be too high, stirring speed should not be too fast, low temperature when the appropriate homogenization can make the product more stable.
Cream Products FAQ.
1 Water loss and dry shrinkage
2 White Labeling
3 Rough paste
4 Water and oil separation
5 Discoloration, odor change
6 mold, swelling, skin irritation
*Disclaimer: The content contained in this article comes from the Internet, WeChat public numbers and other public channels, and we maintain a neutral attitude toward the views expressed in the article. This article is for reference and exchange only. The copyright of the reproduced manuscript belongs to the original author and the institution, and if there is any infringementPlease contact Jetson Chemical for deletion