Cysteamine hydrochloride

Cysteamine hydrochloride (CAS 156-57-0), also known as Merkamin hydrochloride, Mercamine hydrochloride, and 2-aminoethanethiol HCl, is a stable salt form of cysteamine carrying both a free thiol and an amine group. It carries no assigned E-code and is handled commercially under HS code 29309070.

In pharmaceutical manufacturing, it serves as a key intermediate in the synthesis of cysteamine bitartrate, the active ingredient in cystinosis treatments, where the thiol group drives cystine depletion within lysosomes. In food processing, the same thiol reactivity reduces disulfide bonds in wheat gluten, shortening dough mixing time and modifying bread texture without enzymatic agents.

Cysteamine hydrochloride is supplied in pharmaceutical-grade and technical-grade forms, with pharmaceutical material referenced against Ph.Eur. standards. It is a registered REACH substance within the EU. Packaging is available in sealed moisture-barrier containers given the compound's hygroscopic character and sensitivity to oxidation.