Most water-soluble skin care gels are prepared from polyacrylic resin (also known as carbomer) as a gel forming agent. After swelling in water, carbomer is neutralized by triethanol gum and other alkalis to form a water-based gel. On this basis, the following ingredients are often added to the formula:
(1) Solvents: such as glycerol, propylene glycol, ethanol, polyoxalic acid, etc., they can improve the transparency of the colloid and increase the freezing resistance of the product.
(2) Emollients: The biggest difference from skin care creams is that it is difficult to add oily emollients to water-soluble gel formulations. Only some water-soluble emollients can be used in this type of formulation, such as water-soluble silicone oil and polyoxyethylene. (25) Lanolin, water-soluble jojoba oil, polyoxyethylene (20) oleyl ether, etc. Of course, a small amount (1%) of emollient oil can also be added with the help of a solubilizer.
(3) Solubilizer: such as polyoxyethylene (40) hydrogenated castor oil, etc., whose function is to solubilize flavor or a small amount of emollient oil in the hydrocolloid without the system becoming turbid, and its addition can also improve the transparency of the system
(4) Moisturizer: make the product have good moisturizing properties to reduce dry skin. Commonly used humectants are hyaluronic acid, sodium pyrrolidone carboxylate, chitin and so on.
In addition, some nutrients such as acid, vitamin C derivatives, Chinese medicine extracts, aloe vera, etc. are often added to such formulas to improve the effectiveness of water-soluble skin care gels.