This document provides an overview of gastrointestinal agents used to treat various gastrointestinal disorders. It discusses acidifiers that increase acid in the stomach and are used to treat achlorhydria. It also covers antacids that neutralize excess stomach acid and are used for hyperacidity/hyperchlorhydria. Finally, it discusses cathartics/laxatives that relieve constipation through increasing bowel movements. Specific agents covered include ammonium chloride, dilute hydrochloric acid, sodium bicarbonate, aluminum hydroxide gel, and magnesium hydroxide mixture.

1. Pharmaceutical Inorganic Chemistry
Lecture 8
Unit IIl
GASTROINTESTINAL AGENT
⚫ By Manjusha SK
⚫ Associate professor

2. INTRODUCTION
⚫ The gastrointestinal (GI) tract is composed of various organs and tissues
that have different forms and functions.
⚫ It includes the esophagus, stomach, small intestine, large intestine, colon,
rectum, biliary tract, gallbladder, liver, and pancreas.
⚫ The gastrointestinal track suffers from various disorders likeachlorhydria,
hyperacidity, constipation and diarrhea.
⚫ And these disorder s treated with the help of some substances or agent
called as gastrointestinal agents.
GASTROINTESTINAL AGENTS:
⚫ These are the drugs or substances which are used in treatment of various
types of gastrointestinal disorders such as achlorhydria, hyperacidity,
constipation and diarrhea.

4. 1.ACIDIFYING AGENT OR ACIDIFIERS
⚫ Acidifiers or Acidifying agents are the inorganic agent which increases acid
concentration in GI Track (stomach).
⚫ Basically these types of drugs are used in treatment of achlorhydia.
⚫ The empty stomach has pH 1.5 -2 and increases to pH 5-6 when food is
ingested.
⚫ Because of the secretion of HCl the pH of stomach is low.
⚫ Gastric acid act by destroying the bacteria present in the ingested food and
drinks.
⚫ It softens the fibrous food and promotes the formation of the proteolytic
enzyme pepsin.
⚫ This pepsin enzyme Acidifiers or Acidifying agents are the inorganic agent
which either formed or increases acid concentration in GI Track (stomach).
⚫ Acholorhydria: It is an condition in which there is absence or insufficient
secretion of hydrochloric acid in stomach called as achlorhydria.
⚫

5. Classification of Acidifying agent or Acidifiers
⚫ Acidifying agent or Acidifiers are classified in to four types
⚫ Gastric Acidifiers
⚫ Urinary Acidifiers
⚫ Systemic Acidifiers
⚫ Acids
1.Gastric Acidifiers: These are the drugs which are used to increase the acidity of
the stomach in patient suffering from Achlorhydria. So dilute Hydrochloric acid
is used to maintain or raises the level of hydrochloric acid (HCl) in stomach,
thus maintaining proper pH of the stomach.
2.Urinary Acidifiers: These are the drugs which are used to remove acidic urine
from the body or to maintain the Ph of the urine. These type of acidifiers
widely used to cure some type of urinary tract infection (UTI)
3.Systemic Acidifiers: These are the drug which is able to neutralize the alkaline
body fluids, especially blood. These type of acidifiers used to treat patient
suffering from systemic alkalosis.
4.Acids: These are used as pharmaceutical aids in the preparation of
medicaments.

6. 1.Ammonium chloride*
⚫ Method of Preparation:
⚫ 1.It is prepared by neutralization of hydrochloric acid with the help of
ammonium hydroxide and the solution get evaporates to the dryness
followed by crystallization.
⚫ NH4
OH + HCl ---------- NH4
Cl + H2
O
⚫ 2. It is prepared by treating ammonia with hydrochloric acid.
⚫ NH3
+HCl --------------- NH4
Cl
⚫ Assay:
⚫ Principle: Assay of ammonium chloride is performed using argentimetric
titration.
⚫ Reactions :

7. ⚫ Procedure:
Conical Flask: Take a conical flask having 250ml capacity and add 0.1 gm
ammonium chloride & 20 ml distilled water then add 1.5 ml of conc. Nitric
acid, 2.5 ml nitrobenzene & 25 ml (0.1N) sliver nitrate.
Burette: Titrate the above solution using Standardized ammonium thiocynate
solution.
Indicator: 2 to 3 drops of ferric ammonium sulphate.
End point: It is colorless to reddish brown.
⚫ Properties:-
Physical properties: It is….
⚫ White colorless, crystalline or a coarse powder,Odorless.
⚫ Cooling saline in taste,Slightly hygroscopic in nature.
⚫ Very soluble in water, sparingly soluble in alcohol and freely soluble in glycerin.
⚫ Neutral to litmus but become quickly acidic on standing due to hydrolysis.
Chemical properties:
⚫ Ammonium Chloride when heated it loses a acid
⚫ NH4
Cl ----------------- HCl + NH3
⚫ Ammonium Chloride when react with base strong sodium hydroxide it
liberates ammonia gas.
⚫ NH4
Cl + NaOH ---------- H2
O +NaCl + NH3

8. Uses: It is ………
⚫ Used in Maintains of acid-base equilibrium of body fluids.
⚫ showing diuretic effect.
⚫ used as systemic acidifiers.
⚫ used in lead poisoning.
⚫ used in treatment of UTI.
⚫ Used as thickening agent in preparation of hair shampoos.
⚫ Also act as a flavoring agent.
⚫ Also acts as mild expectorant. Therefore in cough preparation it is
used because of local irritation this produces increased secretion of
respiratory tract and makes the mucus less viscous.
⚫ used as emetics.

9. 2.Dilute Hydrochloric acid
Properties:
Physical properties: It is……..
clear, colorless fuming liquid,tasteless.pungent in odour.
soluble in water & alcohol ,acidic to litmus.
Having specific gravity of about 1.18.
Chemical properties: It
Get dissociate at 1500c into hydrogen and chloride
2HCl ---------- H2
+ Cl2
Reacts with ammonia gas to produce white dense fumes.
HCl + NH3
------ NH4
Cl
Uses: It is……
⚫ used as acidifying agent.
⚫ Used as pharmaceutical aid.
⚫ Used as reagent in various strength.
⚫ Used in treatment of achlorhydria.
⚫ Used as solvent.

10. 2: ANTACID
⚫ Antacids are the agent or substances which neutralize the excess of
hydrochloric acid in stomach are called as antacid.
⚫ So it is used in hyperacidity or hperchlorhydria
(Excessive secretion of gastric HCL).
⚫ Antacids which on ingestion react with the gastric acid and lower the acidity of
gastric content.
⚫ They produce a Symptomatic relief of heart burn, pain by neutralizing excess
of HCl.
⚫ Ideal properties / Requirement / Characteristics of antacids:
⚫ Insoluble in water except systemic antacid e.g. sodium bicarbonate
⚫ Should have fine particle size
⚫ should not be absorbable
⚫ should not causes constipation
⚫ should not be act as a laxative
⚫ should exert effect rapidly
⚫ should not causes systemic alkalosis
⚫ Should effect over a long period of time
⚫ Probably inhibit pepsin
⚫ Easily available,Non toxic,Not causes any side effect,Should be stable
⚫ Antacid should be inexpensive and palatable.

11. Classification

12. Sodium bicarbonate
Methods of preparation : A highly concentrated water solution of sodium
chloride is saturated with ammonia to removes impurities, then filtered the
solution and passes through the carbonating tower .In this reaction it is
allowed to interact with a current of CO2 and the tower is cooled to enhance
precipitation. Finally the precipitation is get filtered out and dried.
⚫ Sodium bicarbonate is prepared in laboratory by passing CO2 gas through
sodium hydroxide solution. Finally the solution is concentrated to obtain the
final product.
Assay:
⚫ Principle: Assay of sodium bicarbonate is depends on acid-base reaction. In
which sodium bicarbonate act as weak base and hydrochloric acid act as strong
acid.
⚫ Reaction:
⚫ 2NaHCO3
+HCl --------------- NaCl + 2H2
O + CO2

13. Procedure:
⚫ Conical flask: Dissolve 1.5 gm of sodium bicarbonate in 50 ml
carbon dioxide free water in a conical flask having 250ml capacity.
⚫ Indicator: Add 0.2 ml of methyl orange solution.
⚫ Burette: Titrate the above solution using standardized hydrochloric
acid.
⚫ End point: Solution becomes pink.
Properties:- Physical properties: It is…..
⚫ whitecoloured crystalline powder.
⚫ odourless.
⚫ saline in taste.
⚫ soluble in water.
⚫ insoluble in alcohol.
⚫ basic in nature in aqueous solution.
⚫ having ph 8.2 in aqueous solution

14. Chemical properties:
⚫ It is stable in air but get degrade in presence of heat or moist air.
⚫ 2NaHCO3
-------------- H2
O + CO2
+ Na2
CO3
Uses:- Sodium bicarbonate : It is
⚫ used as systemic antacid.
⚫ used as an electrolyte regenerator.
⚫ used in the treatment of acidosis.
⚫ used as expectorant.
⚫ Helps to produce systemic alkalosis.
⚫ used in eye drops and ear drops formulation to remove the wax.
⚫ used to control vomiting.
⚫ Used used as 1-2% solution for rinsing the contact lens.

15. Aluminium Containing Antacid:
ex. Aluminum hydroxide gel
⚫ Aluminium hydroxide gel:-
Properties –
⚫ Physical Properties: It is…..
⚫ A white, viscous suspension, from which small amounts of clear liquid may
separate on standing.
⚫ translucent in nature.having pH range in between 3-5.sweet in taste.
⚫ Chemical Properties: It is
⚫ When interact with hydrochloric acid to form Aluminium chloride (salt) and
water
⚫ Al (OH)3
+ 3HCl ---------- AlCl3
+ 3H2
O
⚫ Uses:-It is….
⚫ non-absorbable OR non systemic antacid.
⚫ used as mild Astringent & Demulcent when applied externally.
⚫ used as protective in the treatment of Diarrhea & Cholera .
⚫ used as dusting powder when applied externally

16. • Magnesium Containing Antacid:
• Magnesium hydroxide mixture
⚫ Magnesium Hydroxide Mixture
Properties:
⚫ Physical properties: It is…..
⚫ white amorphous powder.
⚫ odorless.
⚫ practically insoluble in water.
⚫ soluble in dilute mineral acids.
⚫ Chemical properties:
⚫ At high temperatures, solid magnesium hydroxide undergoes a very
endothermic (absorbs heat from atmosphere) degradation into magnesium
oxide and water, making it a good smoke suppressing and fire-fighting
agent.
⚫ Mg (OH)2
→ MgO + H2
O
Uses: It is…..
⚫ used as antacid.
⚫ used as laxative.
⚫ Used as Antiperspirant
⚫ used in waste water treatment.

17. 3: CATHARTICS
Saline catharitics : These are the agents/ substances which are used
to relive the constipation.
The term laxative is used for mild cathartic whereas a purgative is
used for strong cathartics.
These are the agent which increases the evacuation of fecal matter
from the bowel by increasing osmotic pressure.
ex. Magnesium sulphate, Sodium orthophosphate, Kaolin and
Bentonite
Classification of Saline cathartics/ Osmotic laxatives
⚫ Sodium containing products- Sodium potassium tartarate, Sodium
phosphate
⚫ Magnesium containing products- Magnesium hydroxide,
Magnesium sulphate, Magnesium Citrate.
⚫ Sulfur as cathartic
⚫ Non official Cathartics- Sodium sulphate, Potassium phosphate.

18. Magnesium sulphate
Properties:-.
⚫ Physical propertires: It is….
⚫ shiny white or colourless needle like crystals
⚫ soluble in water and very soluble in boiling water
⚫ insoluble in most of the organic solvent. odourless.having saline taste
⚫ It evolve efflorescence in dry air
⚫ Chemical Properties:
⚫ The aqueous solution of sodium bicarbonate is treated with magnesium sulphate,
precipitate is not produced, but upon boiling white precipitate of magnesium carbonate is
produced.
⚫ MgSO4
+ NaHCO3 -----------------------
No reaction
boil
⚫ NaHCO3 -----------
Na2
CO3
⚫ Na2
CO3
+ 5MgSO4 ------------------------
4MgCO3.
Mg(OH)2
5H2
O + CO2
Uses:
⚫ About 5gm of magnesium sulphate produces laxative effect.
⚫ It is used as antidote in heavy metal poisoning.
⚫ It is used as saline cathartics.
⚫ It is used in enema.
⚫ It is used as anticonvulsant given by parenteral route.
⚫ It used to reduce pain, inflammation& cramps.

19. Sodium orthophosphate:
⚫ Properties: It is……
⚫ White to off-white powder, crystals, or granules
⚫ It is salt of sodium hydroxide and phosphoric acid.
⚫ Uses: - It is
⚫ used as a laxative.It is used in constipation.
Kaolin
⚫ Properties: - It is…..
⚫ As a soft, white or yellowish white powder,having a clay like earthy taste
⚫ When it is moistened with water, assumes a darker colour,
⚫ insoluble in water, in cool dilute acids or in solution of alkali hydroxide.
⚫ Uses: - It is…….
⚫ used as dusting powder.used as adsorbent.
⚫ used as diluents in tablet formulation.
⚫ used as clarifying agent.used in alkaloidal& food poisoning.
⚫ used in treatment of diarrhea and dysentery.used in treatment of cholera.

20. Bentonite:
⚫ Physical Properties:
⚫ Bentonite is a natural, colloidal, hydrated aluminium silicate
⚫ It is a very fine, pale buff or cream-coloured to greyish-white powder .
⚫ It is insoluble in water,
⚫ It is also insoluble in organic solvents.
⚫ Uses:
⚫ Pharmaceutical aid (suspending agent).
⚫ Bentonite is used as a binding agent in the production of iron ore
pellets.
⚫ It acts as lubricant agent.
⚫ It is used in production of cement and mortars.
⚫ It is used in waste water purification.
⚫ It is used in extraction of oils.
⚫ Bentonite is used as an antidote in heavy metal poisoning.

21. 4.ANTIMICROBIALS
Antimicrobial agent: The substances which are used to kill microorganisms are
called antimicrobial agents.
Such as Hydrogen peroxide, potassium permagnate, chlorinated lime. Etc.
⚫ Classification of antimicrobial agent
⚫ Antiseptics: Substances or agent that have the power to kill the microbes and
stop the expansion of microbes once applied on living material, for example
oxide like Hydrogen peroxide
⚫ Disinfectant: Substances or agent that have the power to kill microbes and
stopthe expansion of microbes when applied on non- living material/
inanimate object, for example cresol.
⚫ Bactericidal: Substances or agents that have the power to kill bacteria for
examplePot. Permagnate.
⚫ Bacteriostatic: Substances or agent that have the ability to prevent the
growth of the bacteria, for example Borax
⚫ Fungicidal: Substances or agent that have the power to kill the fungi for
example Iodine
⚫ Fungi static: Substances or agent that have the ability to prevent the growth
of the fungi.
⚫ Germicide: Substances or agent that have the power to kill the germs for
example Iodine

22. Potassium permagnate :-
Properties :-
⚫ Physical Properties: It is….
⚫ occurs as darker purple, slender, prismatic by a dark bronze like
appearance. odorless.
⚫ Having sweet and astringent taste. soluble in water.
⚫ Chemical Properties:
⚫ Potassium acts as strong oxidizing agents
⚫ KMnO4
+ H2
O + KI → 2 MnO2
+ KIO3
+ KOH
⚫ 2 KMnO4
+ 10 KI + 8 H2
SO4
→ 6 K2
SO4
+ 2 MnSO4
+ 5 I2
+ 8 H2
O
⚫ Uses: It is…
⚫ used as disinfectant and deodorant due to its strong oxidising
properties.
⚫ also used as astringents, anti-infective and bactericidal.
⚫ Used as a bleaching agent.
⚫ used extensively in the water treatment.
⚫ Used in the form of aqueous solution for gargles and as mouth wash.

23. Boric Acid
Physical properties:It is…..
⚫ white crystalline powder with soapy touch.
⚫ odourless and stable in air. bitter in taste
⚫ soluble in boiling water & freely soluble in Glycerine.
⚫ slightly acidic in nature.(Ph between 3.8-4.8)
⚫ Chemical properties:
⚫ Boric acid is soluble in boiling water. When heated above 1000
C it converted to
metaboric acid (HBO2
) and when metaboric acid heated at 1600
C it converted into
tetraboric acid or pyroboric acid (H2
B4
O7
) and when pyroboric acid is heated above
2000
C it degrade into boron trioxide (B2
O3
):
Uses:
⚫ used in preparation of buffer solution.
⚫ used in various topical medications to maintain acidic pH
⚫ Dusting powder as ingredient because boric acid has smooth unctuous nature
⚫ used mainly as eye & mouth wash for local anti-infective action in the form of solution
⚫ used as Insecticide

24. ⚫ Chlorinated lime (Bleaching powder); Method of Preparation:
⚫ Calcium hypochlorite is produced industrially by passing chlorine gas in to calcium
hydroxide (slaked lime) to produce chlorinated lime.
⚫ 2 Cl2
+ 2 Ca(OH)2
→ Ca(OCl)2
+ CaCl2
+ 2 H2
O
⚫ Assay: Principle: Assay is based on Iodometric type of titration.
⚫ Reaction: 2KI + Cl2
---------- 2KCl + I
⚫ Na2S2O3 + I2
--------- Na2
S4
O6
+ 2NaI
⚫ Procedure: Conical flask: Chlorinated lime react with carbon dioxide and chlorine gas is
liberated it further react with potassium iodide to liberate Iodine
⚫ Burette:0.1 N Sodium thiosulphatesolution.
⚫ Indicator:Starch paste. End point:Violet colour.
⚫ Properties :- Physical properties: It is….
⚫ white/gray powder. Having strong odour of chlorine.
⚫ on expose to air it becomes moist ,sparingly soluble in water and soluble in alcohol.
⚫ Chemical properties:
⚫ When calcium hypochlorite react with hydrochloric acid to produce calcium chloride,
water and chlorine:
⚫ Ca(OCl)2
+ 2HCl CaCl2
+ H2
O + Cl2

25. Uses: It is….
⚫ Used to kills most of the bacteria, some fungi, yeast, algae, viruses and protozoa.
⚫ commonly used to sanitize public swimming pools and disinfect drinking water.
⚫ is also used in kitchens to disinfect surfaces and equipment. used in preparation of
detergents
⚫ used as bleaching agent, to decolorize most of dyes.
⚫ Used as bathroom cleansers, household disinfectant sprays, algaecides and herbicides.
Iodine:
⚫ Properties of Iodine: Physical properties: It is….
⚫ a heavy, greyish violet, brittlele, plates or metallic luster/ small crystals.
⚫ having metallic shine, irritating odour ,volatizes at ordinary room temperature.
⚫ Melt at higher or room temperature, snsoluble in glycerine , very slightly soluble in
water
⚫ Chemical properties: It….
⚫ Produces various forms of iodates such as Fe, Hg,Pb, etc
⚫ 3Fe + 4I2 -------------------
Fe3
I8
, Hg + I2
---------- Hg I2
and Pb+ I2
----------Pb I2
⚫ Use / Role: It is used in treatment of goiter.
⚫ Used as antimicrobial agent.
⚫ Used as germicides & fungicide in the form of aqueous & alcoholic solution.
⚫ Used in purification of drinking water.
⚫ Used as bacteriocidal and amoebicidal.
⚫ Used for disinfecting unbroken skin.

26. ⚫THANK YOU