terpin hydrate

Terpin hydrate is a monoterpene diol, historically derived from the oxidation of turpentine oil or isolated from plants such as *Aristotelia chilensis*, that served as a staple expectorant in respiratory medicine for decades. It is primarily recognized for its ability to stimulate the secretory glands of the bronchial mucosa, which increases the volume of respiratory tract fluid and facilitates the clearance of viscous mucus. Additionally, it has been studied for potential bronchospasmolytic effects and antidotal action against nicotine. Most commonly administered as an oral elixir, it was frequently paired with codeine or dextromethorphan hydrobromide to manage coughs associated with bronchitis and the common cold. Despite its long history of use, the U.S. FDA reclassified terpin hydrate in the 1990s, removing it from the over-the-counter (OTC) monograph for expectorants due to a lack of substantial evidence demonstrating its clinical efficacy, which led to its widespread discontinuation in many pharmaceutical markets. Rare reports of liver injury have been associated with its use, particularly in combination elixirs. It is also found as a natural aroma component in certain beverages like cola and has been noted for its properties as an ice nucleator in atmospheric science. In research, it has been used as a standard substance in ciliate mobility tests to evaluate the effects of harmful substances on respiratory ciliated epithelium. Furthermore, it can be produced through the biotransformation of monoterpene alcohols by various yeast species during fermentation processes. A related product, Ozothin, consists of standardized oxidation products of turpentine oil and terpin hydrate and has been used to liquefy viscous secretions in chronic obstructive lung diseases.

Brand names

Terpin Hydrate Elixir

Other names

cis-terpin hydrateterpinum hydratum1,8-terpin hydratedipentene glycol