Why Are So Many Medications Something Hydrochloride?

Almost every medication I look at is SOMETHING Hydrochloride. What’s up with this? Sound suspiciously like hydrochloric acid to me. Is this some Al Quidia plot?

Hydrochorides are used for the following reasons:
1> Tradititionally pharmaceuticals are crystallized from solution.
2> Hydrochloric Acid is already present generated in your alimentary canal (bile), so making hydrochloric acid salts put no new ionic species.
3> Hydrocholiric Salts make medicines more water soluble and stable for storage.

Hope that helps

4> Many drugs contain parts that are acidic and parts that are basic. These plus and minus charges all need to be neutralized with something. Hydrochloric acid is convenient for this purpose.

The key word here is neutralized. Once the HCl has reacted with the drug it is no longer hazardous.

Also, enteral drugs are usually designed to be absorbed in the intestines, so making them more acidic (with the HCl) allows them to pass through the stomach relatively unchanged.

Is it just me, or are Squink’s and St. Urho’s replies at odds with each other?

I think what both are saying is that the chemical used to pH the drugs is HCl. When a drug is synthesized it can be very basic which affects its charge. I’m guessing the drug is pH’ed to near stomach acid pH or to it’s pI, which is the pH at which a molecule’s charge is neutral (thus absorbing easier - charges don’t go through the lipid bilayer of cells easily).

HCl doesn’t have to be used, in my lab I usually use acetic acid (and thus label my chemicals Tris-acetate pH 8.0, etc).

“I’m guessing the drug is pH’ed to near stomach acid pH or to it’s pI”
Or neutral pH. The choice of pH and of counterions depends on the structure of the drug, and also on how it is administered.

many pharmaceutical drugs contain basic nitrogens. However, in their native state they are fairly insoluble in water, and basic. By adding HCl, it puts a charge on the drug. This allows it to break down quicker and disperse in the stomach (or blood if it is injected). It also stops the basic drug irritating the membranes.

As I recall, normally cocaine is in its HCl (or HSO4) form, allowing it to dissolve and cross the membranes quickly. However, this makes it non-volatile, so to smoke it you need the free base form (no HCl).