Why is it that a lot of prescription medicine that I have seen advertized on TV is brand name HCl? Also when I did a search to try to find out, all I turned up was masses of other medicine that have HCl. Why is it so common, and why does a lot of medicines have it following the brand name?
These drugs are “amines” that are reacted with HCl to produce an acid salt. This is done because the acid salt is generally more stable and soluble in water than the parent amine.
The formula for such salts is generally written as “AHCl”, where “A” represents the parent amine. The salt ammonium chloride (NH[sub]4[/sub]Cl) could be written this way as (NH[sub]3[/sub]HCl). If ammonium chloride were being named by a pharmaceutical company, they might call it “ammonia HCl.”
Some examples of amines that are drugs include ephedrine, codeine, and novocaine.