Excipient (pharmacologically inactive substance)
What is it?
Glycerol (C3H8O3), also known as glycerin and glycerine, is an odorless, colorless, oily, viscous liquid that has a sweet taste.
Synthetic glycerine is used in food products, nutritional supplements, pharmaceutical products, personal-care products, and oral-care products. In the pharmaceutical industry, glycerin is used as a sweetener in syrups, lozenges, and as an excipient in eyewash solutions. It my also be found in ear drop products, jellies and creams for topical use, in expectorants for congestion, suppositories, and gel capsules. As an individual prescription product, glycerin has uses as a hyperosmotic, osmotic diuretic, and ophthalmic agent. It may be used as eye drop in the treatment of glaucoma to reduce the intraocular pressure, as a solution or suppository for short-term treatment of constipation or to evacuate the bowel, and in some ocular surgeries. It may be given intravenously to reduce pressure inside the brain, and used externally on the skin as a moisturizer. Glycerin has many other uses in the agricultural, food and pharmaceutical industry.
Glycerin is classified by the U.S. Food and Drug Administration (FDA) as generally recognized as safe (GRAS). The overall risk of toxicity from glycerin found in pharmaceutical products is low. If one were to come into contact with bulk quantities of glycerin, eye irritation may occur. Skin irritation is unlikely unless the skin is damaged. Inhalational toxicity is low due to low volatility, but prolonged ingestion can cause elevated blood sugar or fat levels in the blood.
 Dow Chemical. Glycerine. Product Safety Assessment. Accessed April 14, 2012. http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_01ad/0901b803801ade92.pdf?filepath=productsafety/pdfs/noreg/233-00490.pdf&fromPage=GetDoc