Carbopol 940,also called Carbomer or Carboxypoly-methylene is a generic name for synthetic high molecular weight polymers of acrylic acid used as thickening, dispersing, suspending and emulsifying agents in pharmaceuticals and cosmetics. They may be homopolymers of acrylic acid, crosslinked with an allyl ether pentaerythritol, allyl ether of sucrose or allyl ether of propylene.
Carbomers are found in the market as white and fluffy powders. They have the ability to absorb, retain water and swell to many times their original volume. Carbomers codes (910, 934, 940, 941 and 934P) are an indication of molecular weight and the specific components of the polymer .
Carbomer 940 is used for topical formulations and suitable for preparation of gels, creams and coupling agent. Carbomer and cross-linked acrylic resin as well as series products of these cross-linked polyacrylic acid are widely used at present and are often used in topical lotion, cream and gel. In a neutral environment, Carbomer system is an excellent gel matrix with crystal appearance and nice sense of touch, so Carbomer is suitable for preparation of cream or gel.