Hydrochloride

Overview

In chemistry, hydrochlorides are salts resulting, or regarded as resulting, from the reaction of hydrochloric acid with an organic base (mostly amines). This is also known as muriate, derived from hydrochloric acid's other name: muriatic acid.

For example, reaction of pyridine (C₅H₅N) with hydrochloric acid (HCl) yields pyridine hydrochloride (C₅H₅N·HCl). Even though this style of formulas is often used for denoting the hydrochlorides, the dot incorrectly implies that the two molecules are weakly bonded together. It is the salt C₅H₅NH⁺ Cl^- with correct chemical name pyridinium chloride.

Uses

Converting otherwise insoluble amines into their hydrochlorides is a common way to make them water- and acid-soluble. This is particularly desirable for substances used in medications. Many pharmaceutical substances used are prepared as hydrochlorides so that they may be quickly absorbed in the gastrointestinal tract. The typical breadth of time needed for a hydrochloride to be absorbed thusly is 15-30 minutes.

Examples of hydrochlorides in medical uses are many, ranging from over-the-counter sinus relief to antinausea medication used mainly in the pre-treatment of chemotherapy-induced nausea and vomiting (Zofran, Ondansetron hydrochloride).