ANTACID INTRODUCTION IDEAL PROPERTIES OF ANTACID CLASSIFICATION OF ANTACID VARIOUS COMPOUND USED AS ANTACID

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

2. INTRODUCTIO
N
Antacid are the alkaline substance, which after administration it react with gastric
acid and neutralize it and lower the acidity of gastric juice.
These are the weak base and increase the pH above 4 by neutralizing excess of
hydrochloric acid which may cause pain , ulcer in stomach.
If antacid are water soluble, they produce systemic alkalosis because of absorbable
ion it disturb acid base balance in body fluid.
All antacid are water soluble except sodium bicarbonate.
Antacid give relief from pain by neutralizing excess acid. That’s why it used in
treatment of ulcer.

3. Gastric Acidity result in : -
Gastritis / Gastric Ulcer / Duodenum Ulcer
Alcohol consumption
Eating certain food / Smoking
Some drugs like aspirin / Stress
Symptoms of Gastric Acidity : -
Uneasy feeling
Heart burn
Growing hungry even after meal

4. Ideal characteristic / property of Antacid : -
 should be insoluble in water
Having fine particle size
Should not get absorbed
Should not liberate Carbon dioxide
Should neither be laxative nor constipative in action
Should give quick action
Should produce longer duration action
Should be stable
Should be easily available
Should be non toxic

5. CLASSIFICATION OF ANTACID
Antacid generally classified in TWO types :-
1. Systemic antacid (Absorbable)
2. Non systemic antacid (Non absorbable)

6. SYSTEMIC ANTACID (ABSORBABLE)
This type of antacid get absorb systematically.
These are highly soluble and potent neutralizer.
These are not suitable for treatment of peptic ulcer because of risk of
ulcer perforation occur due to production of carbon dioxide gas in
stomach.
e.g. Sodium carbonate

7. NON SYSTEMIC ANTACID (NON
ABSORBABLE)
These are the insoluble and poorly absorbed systematically.
E.g. Magnesium and Aluminum salt
Further classified as :-
Aluminum containing antacid
Calcium containing antacid
Magnesium containing antacid
Combination antacid

8. ALUMINUM CONTAINING ANTACID
It’s a weak and slow reacting antacid
Aluminum ion relax smooth muscle and cause constipation
Aluminum hydroxide
Aluminum phosphate

9. CALCIUM CONTAINING ANTACID
Calcium carbonate potent antacid and having rapid neutralizing
action on acid.
It increase pH of gastric to 7. it not cause systemic alkalosis.
But for long term use it cause hypocalcemia , hypercalciuria and
formation of calcium stone in kidney.
Carbonate present in intestine leads to constipation. To counteract
this problem, given in combination with magnesium antacid.
Calcium carbonate
Tribasic calcium phosphate

10. MAGNESIUM CONTAINING ANTACID
Magnesium carbonate is a water soluble and react with HCl at a slow
rate.
Magnesium hydroxide has low solubility and has power to absorb and
inactivate pepsin.
Magnesium carbonate
Magnesium hydroxide
Magnesium trisilicate
Magnesium phosphate

11. COMBINATION ANTACID THERAPY
Single antacid do not posses all ideal property of antacid. In market
the product available is in combination.
Single calcium and aluminum antacid have constipation action.
Magnesium have laxative effect.
To overcome this problem, need to take in combination. In
combination it produce rapid onset of action.
Brand Name Ingredient
GELUSIL Aluminum hydroxide and
magnesium hydroxide with M.P.S.
DIGENE
SILOXOGENE Aluminum hydroxide and
magnesium hydroxide with
Simethicone

12. 1. Antacid are alkaline base which neutralize excess acid in stomach by raise pH of
gastric above 3.5. as we know pepsin help in digestion of food at pH below 3.5
Because of antacid pH get higher it cause digestion problem.
2. If antacid water soluble so it get absorb easily in body fluid shows alkaline nature
and acid base imbalance happen.
3. Antacid contain sodium ion and if person on restricted sodium diet cause excess
administration of sodium as antacid having sodium (Hypernatremia)
4. Local effect of antacid on GIT tract. Calcium and aluminum having constipation
effect while magnesium having laxative effect.
To overcome all above problem, combination antacid therapy used.

13. Combination preparation –
1. Compound magnesium trisilicate powder
2. Magaldrate (aluminum hydroxide and magnesium hydroxide)
3. Algicon tablet (chewable tablet)
4. Simeco tablet

14. SODIUM BICARBONATE
Chemical formula – NaHCO3 Molecular
weight – 84.01
Synonym – Baking soda
Property –
 Color – white crystalline powder
 Odour – odorless
 Taste – saline taste
 Solubility – soluble in water in small extent / insoluble in

15. Method of preparation –
 Medicinally useful sodium bicarbonate prepared from pure sodium
carbonate. A solution of sodium carbonate is saturated with carbon
dioxide. The reaction mixture is cooled. Result in precipitation of sodium
bicarbonate.
Na2CO3 + CO2 + H2O 2NaHCO3
Assay –
 It is analyzed by acid base titration, solution of compound (2.0 gm in
50ml CO2 free water) is titrated with 0.5 N H2SO4 using methyl orange as
indicator.

16. Uses –
 Used as antacid
 It used to neutralize excess HCL
 Used in treatment of systemic acidosis
 Used as electrolyte replenisher
 5% solution used in ear drop to soft ear wax.
 3.5% solution in warm water used in eye lotion.
 Its ingredient in effervescent antacid preparation. e.g. ENO

17. ALUMINUM HYDROXIDE GEL
Chemical formula – Al(OH)3 Molecular weight – 77.99
Property –
 Aqueous white viscous suspension of hydrated aluminium oxide with
different amount of basic aluminium carbonate and aluminium oxide.
 It also contain sodium benzoate as a preservative.
 It contain menta oil, peppermint oil as a flavouring agent.
 It contain sucrose, glucose, saccharine as a sweetening agent.
 Having pH range 5.5 – 8.0.

18. Uses –
 Used as antacid
 Used in treatment of diarrhoea, cholera.
 Externally it used as mild astringent and desiccant.

19. MAGNESIUM HYDROXIDE MIXTURE
Synonym – Milk of magnesia / cream of magnesia
It’s a bulky white powder insoluble in water and alcohol. Soluble in dil. Acid.
8% w/w oral suspension of hydrated magnesium oxide, prepared by following method
:
Rx
Magnesium sulphate 47.5 gm
Sodium hydroxide 15 gm
Light magnesium oxide 52.5 gm
Chloroform 2.5 ml
Purified water Q.s. 1000 ml

20. Method of preparation –
 Dissolve sodium hydroxide in 150ml water.
 Add light magnesium oxide.
 Mix it to form smooth cream, add sufficient water to produce 2500ml.
 Pour this suspension in thin stream into solution of magnesium sulphate
with continuous stirring.
 Allow precipitate to subside. Decant clear liquid. Transfer residue to
calico strainer.
 Allow draining and washing the precipitate with purified water until all
sulphate are washed away.
 Mix the washed precipitate with water.
 Dissolve chloroform in mixture and add sufficient water to produce
1000ml.

21. Uses –
 Used as antacid.
 Give relief in hurt burn
 Give relief in indigestion problem
 Also used in stomach ulcer or stomach cancer.