Google Answers Logo
View Question
Q: What does the HCL desigantion after a drug name stand for? ( Answered 4 out of 5 stars,   1 Comment )
Subject: What does the HCL desigantion after a drug name stand for?
Category: Health
Asked by: pepsii-ga
List Price: $5.00
Posted: 11 Nov 2005 06:20 PST
Expires: 11 Dec 2005 06:20 PST
Question ID: 591870
What does the HCL desigantion after a drug name stand for?  I always
thought HCL was the chemical abbreviation for hydrochloric acid.

Request for Question Clarification by rainbow-ga on 11 Nov 2005 06:53 PST
HCL stands for hydrochloric acid or hydrochloride.

See here:

hydrochloric acid (hy·dro·chlo·ric ac·id) (hi?dro-klorŽik)  a term
applied to aqueous solutions of hydrogen chloride, HCl. It is a highly
corrosive strong mineral acid commonly used as a laboratory reagent.
HCl is secreted by the gastric parietal cells in response to gastrin,
histamine, and vagal stimulation. This normally reduces the pH of the
gastric content to below 2.0.

hydrochloride (hy·dro·chlo·ride) (hi?dro-klorŽ?d)  a salt formed by
addition of hydrochloric acid; chemically it is a chloride salt of the
moiety formed by protonation of a neutral organic compound. The term
hydrochloride is used primarily in drug names.

Does the above information suffice as an answer to your question?

Best regards,
Subject: Re: What does the HCL desigantion after a drug name stand for?
Answered By: czh-ga on 11 Nov 2005 14:45 PST
Rated:4 out of 5 stars
Hello pepsii-ga,

You?re right in recognizing HCL as the abbreviation of hydrochloric
acid. When used on over-the-counter medication labels, HCL is a
designation for hydrocholoride. Medications that are hydrochlorides
are salts that result from the reaction of hydrochloric acid with an
organic base used to produce the particular drug. This form of the
drug is usually more water soluble than the free form of the chemical.
I?ve found a discussion in Google Groups that asked this same question
that should be helpful. I?ve also included some links to a few basic
chemistry links and to rules about naming conventions for drugs.

I trust this will help you with reading medication labels.

All the best.

~ czh ~
Why the Hydrochloride Salt?

Akilli -- Jun 20 1998, 11:00 pm 
Newsgroups: sci.chem
From: (Akilli) 
Date: 1998/06/21
Subject: Why the Hydrochloride Salt?


Just a casual look at the generic names of  medications shows  many 
which terminate in "hydrochloride". Is there some reason (solubility?) which 
determines the choice of a hydrochloride salt?  
This is probably a quite standard procedure in chemistry, but, as a 
non-chemist, (just one of my myriad of non-professions) it is something I have 
always been curious about, and would appreciate an explanation, or comment upon 
my assumptions. 
                                                                 Much Obliged, 
                                                                 Ethan Gross 


Bruce Hamilton
Jun 20 1998, 11:00 pm 
Newsgroups: sci.chem
From: (Bruce Hamilton)
Date: 1998/06/21
Subject: Re: Why the Hydrochloride Salt? (Akilli) wrote: 
>         Just a casual look at the generic names of  medications shows  many 
>which terminate in "hydrochloride". Is there some reason (solubility?) which 
>determines the choice of a hydrochloride salt?     

Pharmaceuticals are often available as either the "free" form, or 
as a salt. The hydrochloride forms are usually both more water 
soluble and stable in formulations than the free form, and 
traditionally, recrystallising salts was a common method of 
purifying chemicals. One requirement is that chemicals should be 
anemable to, and able to withstand, the conditions during 
formulation, and many of the "free" forms of chemicals are not 
solids and may also react with other components. 
For those pharmaceuticals taken orally, the hydrochloride forms 
also can't cause significant increases in concentration of 
a minor ionic species when encountering the hydrochloric acid 
in our stomach, and thus it's easier to exclude such effects 
during approval testing if *HCl forms are used. 
Although *HCl is common, there still are a lot of other forms 
used, depending on the desired properties, eg codeine phosphate. 
        Bruce Hamilton 

***** See other four comments as well for a broader discussion.


I. Valid Drug Terms
	A. Naming Conventions
	B. Naming Rules
	C. Naming Drug Classes
	D. Acceptable Abbreviations for Use in Valid Drug Terms
		Abbreviation    Word/Phrase
		 -- HCL		 -- Hydrochloride

***** When a drug label includes HCL as part of the name of the
medication, the medication is a hydrochloride. There are many
medications that fit this classification.


In chemistry, hydrochlorides are salts resulting, or regarded as
resulting, from the reaction of hydrochloric acid with an organic base
(mostly amine).

Converting otherwise water-insoluble amines into hydrochlorides is a
common way to make them water-soluble. Many pharmaceutical substances
are used as hydrochlorides.

Hydrochloric acid

The chemical substance hydrochloric acid is the aqueous (water-based)
solution of hydrogen chloride (HCl) gas. It is a strong acid, the
major component of gastric acid and of wide industrial use. As a
highly corrosive liquid, hydrochloric acid should be handled only with
appropriate safety precautions.

Production of organic compounds
The largest hydrochloric acid consumption is in the production of
organic compounds such as vinyl chloride for PVC, and MDI and TDI for
polyurethane. This is often captive use, consuming locally produced
hydrochloric acid that never actually reaches the open market. Other
organic compounds produced with hydrochloric acid include bisphenol A
for polycarbonate, activated carbon, and ascorbic acid, as well as
numerous pharmaceutical products.


drugs OR medications "naming conventions" hcl
pepsii-ga rated this answer:4 out of 5 stars and gave an additional tip of: $2.00
Thanks, and good explaination. Now I understand the usage in pharma as well.

Subject: Re: What does the HCL desigantion after a drug name stand for?
From: czh-ga on 12 Nov 2005 13:09 PST
Hello pepsii-ga,

I'm glad the explanation was useful. Thanks for the generous tip.

~ czh ~

Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  

Google Home - Answers FAQ - Terms of Service - Privacy Policy