This document discusses acidifying agents used to treat conditions caused by low stomach acid such as achlorhydria. It describes two main acidifying agents - ammonium chloride and hydrochloric acid. Ammonium chloride is used as a systemic acidifier, expectorant, and diuretic. It is prepared by neutralizing hydrochloric acid with ammonia. Hydrochloric acid is used as an acidifying agent, solvent, and catalyst. It is prepared by reacting sulfuric acid with sodium chloride. Both agents work to increase stomach acid levels and support digestion when acid production is impaired.

1. GASTRO INTESTINAL AGENT
ACIDIFYING AGENT
BY
TAUFIK MULLA
Asst. Professor
Department of Pharmaceutics
SPBC college of Pharmacy

2. INTRODUCTION
Gastrointestinal tract is a one of the
organ of body.
Git involves in digestion of food,
from the ingestion to excretion.
Parts of GIT :
Esophagus
Stomach
Intestine
Rectum with anus

3. In case, if function of GIT impaired / imbalanced, following
condition can take place :
Decrease secretion of HCl in stomach leads to Achlorhydria or
Hypochlorhydria.
Excess secretion of HCl in stomach leads to hyperacidity which cause ulcer,
inflammation and pain.
Incomplete absorption of food or fluid or electrolyte in intestine cause
stimulation of intestinal motility which leads to diarrhea or frequent stool.
Insufficient intestine motility cause constipation.
Inadequate secretion of saliva cause difficulty in swallowing food.

4. To overcome this GIT related problems / disease various agents are
used as follows :
Classification of gastro intestinal agent –
1. Acidifying agent e.g. – Hydrochloric acid , Ammonium Chloride
2. Antacid e.g. – Sodium bicarbonate , Aluminum hydroxide gel
3. Saline cathartics e.g. – magnesium Sulphate , Kaolin , Bentonite
4. Antimicrobial e.g. – KMnO4 , Hydrogen peroxide , Chlorinated lime

5. ACIDIFYING AGENT
In digestion of food, important constituent of gastric juice is PEPSIN enzyme
and HCl.
Small quantity of gastric juice present in stomach when it doesn’t contain
food, this state called as fasting juice.
Pepsin effective in acidic environment pH below 3.5.
Pepsin inactive if pH is high.
HCl secreted by stomach wall (parietal cell of stomach). Kill bacteria in
ingested food/drink, make fibrous food soften and help in secretion of
PEPSIN enzyme.

6. ACIDIFYING AGENT
Acidifying agent are used in a condition when there is absence or insufficient
secretion of Hydrochloric acid in stomach which leads to a disease called as
Achlorhydria or Hypochlorhydria.
HCl secretion is in control of acetylcholine, histamine and gastrin.
Gastric acid secretion is governed by histamine receptor, muscarinic receptor and
gastrin receptor.
Chemical agent which used as acidifying agent are :-
Ammonium chloride
Hydrochloric acid

7. Acidifying agent are classified as :-
Gastric acidifier – drug which used to restore acidity of stomach
in patient suffering from achlorhydria or hypochlorhydria.
Urinary acidifier – drug used to retain acidity of urine to enable
treatment of some of urinary tract disorder.
Systemic acidifier – drug used to neutralize alkaline body fluid.
Acid – drug used as pharmaceutical aid in preparation, laboratory
, quality control etc.

8. AMMONIUM CHLORIDE
Chemical formula – NH4Cl Molecular
weight – 53.49
Synonym – ammonium muriate / salmiac / amchlor
Properties –
Color - white fine crystalline powder
Odour – odorless
Taste – cooling saline taste
Solubility – soluble in water , slightly soluble in alcohol.

9. Method of preparation –
 it is prepared by neutralizing HCl with ammonia.
NH3 + HCl NH4CL
Assay –
 Assay done by acid base type of titration. The neutral
formaldehyde solution is added. So ammonium chloride will be
converted in methenamine and hydrochloric acid. The liberated
acid is titrated with 0.1N NaOH using phenolphthalein indicator.

10. Uses –
 Used as systemic acidifier.
 It used as expectorant
 Is used as a diuretics.

11. HYDROCHLORIC ACID
Chemical formula – HCl Molecular
weight – 36.5
Synonym – muriatic acid / spirit of salt
Properties –
Color - colorless clear fuming liquid
Odour – pungent odor
Solubility – soluble in water , alcohol.

12. Method of preparation –
 it is prepared by action of sulphuric acid on sodium chloride.
H2SO4 + 2NaCl Na2SO4 + HCl
Uses –
It used as pharmaceutical aid.
It is used as acidifying agent.
It also used as solvent.
It used as catalyst in basic pharmaceuticals.