Silicon dioxide is one such. Compression aids help to make pills hold their shape upon compression and improve compressibility properties in general. Colors include a wide variety of dyes and coloring agents from among the more than 100 approved by the FDA for pharmaceutical use. Allergic reactions to these compounds have been shown to be a potential problem for some patients. These hypersensitive responses include contact dermatitis, abdominal pain and vomiting, and even anaphylaxis.
Sweeteners are extremely common in oral medications.
Aspartame, fructose, saccharin, sorbitol, and sucrose are the most commonly used sweeteners in the United States. The sugar-free sweeteners are especially important for chronic medication to prevent dental caries and, of course, are necessary for diabetic patients. Preservatives are chemicals that are added to drug products to prolong shelf life and maintain sterility. The antimicrobials include chlorobutanol, benzyl alcohol, sodium benzoate, sorbic acid, and phenol. The antioxidizing agents include butylated hydroxytolune, hydroxyanisole, propyl gallate, and sulfites.