USP Glycerin is a pharmaceutical grade, versatile alcoholic compound. Its official IUPAC name is propane-1,2,3-triol. Glycerin’s chemical formula is (HOCH2)2CHOH and its CAS number is 56-81-5. This sweet but odorless alcohol is used primarily for food and beverages as a humectant and/or additive. It makes a good alternative sweetener because it doesn’t induce hyperglycemia (or elevated blood sugar level) nor feeds plaque-forming bacteria. As sweet as table sugar by 60 percent, it only contains approximately 27 calories per teaspoon. It is used to produce snus, a Swedish snuff, together with propylene glycol. Its polyglycerol esters are made into shortenings, margarines, and emulsifiers.
Medical, pharmaceutical, and cosmetic preparations primarily mix USP glycerin as humectant, lubricant, or gloss. It is blended in cough syrups, expectorants, toothpastes and oral care products, lotions, shaving foams, hair care products, and water-based personal lubricants. Glycerin is also used as a caking agent in solid medical preparations such as pills. It is a popular laxative in suppository or enema form as well. Glycerin also prevents liquefaction of tannins in herbal tinctures, or ethanol extracts of plants. It can also be a good substitute for ethanol as a solvent in herbal extraction preparations. Because of its bacteriostatic action, it is also a stable preservative for botanical products. When utilized in proper concentrations in an extraction solvent base, food grade glycerin does not allow chemical breakdown of a finished extract’s components over several years.
