Glycerin, also known as glycerol, is a versatile and widely used active pharmaceutical ingredient in compounded formulations. It is a simple polyol compound that is colorless, odorless, and has a sweet taste, making it an ideal excipient in various pharmaceutical applications. Glycerin is renowned for its hygroscopic properties, which means it can attract and retain moisture, making it an excellent humectant in topical formulations.

In addition to its moisturizing capabilities, glycerin serves as a solvent, sweetening agent, and preservative in many compounded medications. Its ability to enhance the solubility of other active ingredients makes it a valuable component in oral, topical, and injectable formulations. Glycerin is also known for its low toxicity and high biocompatibility, which contributes to its widespread use in both human and veterinary medicine.

For prescribers, understanding the role of glycerin in compounded formulations is crucial, as it can influence the stability, efficacy, and patient acceptability of the final product. Its inclusion in formulations can improve the texture and spreadability of topical preparations, enhance the palatability of oral medications, and ensure the homogeneity of injectable solutions. Glycerin's multifunctional nature makes it an indispensable ingredient in the compounding pharmacy setting.