Cosmetics

When a lipstick containing alginate and calcium is applied to the lips, the alginate contained in the lipstick dissolves due to moisture such as exhaled breath and saliva, and then reacts with calcium to form a gel. The result is an alginate gel coating on the lipstick surface.
As the surface of the lipstick-coated lips is coated with an alginate film, the lipstick does not transfer to a cup or glass when drinking and the cosmetic lasts longer.

When an alginate solution is dripped into an aqueous solution of calcium salt, spherical gel beads are made. Fine micro-beads with a diameter of about 10 μm are processed by the same principle and are used as substrates for cosmetics. Dried microbeads are porous and do not melt or swell in the presence of water and, in fact, they release their moisture when their surroundings become dry, a property similar to breathing. Formulated with these microbeads, foundations have been commercialized that are free from sweat loss and as an antiperspirant spray with a skin feel that is supple even when sweat is absorbed.

Alginate is used as a binder in toothpaste. Several thickening polysaccharides are used as binders to prevent dentifrice ingredients (such as abrasives) from precipitating and to maintain quality during storage. Among these, alginate has the smoothest solution fluidity, it does not stick in the oral cavity when used and it has a reputation as a binder that provides a refreshing feeling.

Alginate is also used in peel-off face packs where a paste-like pack is applied to the face and peeled off together with dirt and impurities. Typical peel-off packs must wait until the applied paste is dry and film-like, but with alginate, the pack gels into sheets on the surface of the face, thus drying of the pack is not required.

By adding water to the powdered pack and kneading it, the alginate dissolves and after it is applied to the face, it reacts with the calcium salt to form a gel. Due to the good fluidity of the alginate solution, the applied pack spreads all over the skin and moisturizes the skin. Then, it gels and is peeled off trapping dirt and impurities.

The gelation reaction of alginate and calcium is used to produce fine fibers which are then processed into nonwoven fabrics and used in face pack sheets. Alginate fibers impregnated with skin care ingredients are soft when swollen, making the face pack less irritating to the skin and feeling good to use.