ANTACID AND ITS PREPARATION

HELPFUL FOR B PHARMACY AND D PHARMACY

1. PHARMACEUTICAL INORGANIC CHEMISTRY
B PHARMACY 1
ST
SEM
ANTACID AND ITS PREPARATION
SURAJ KUMAR SHRIVASTAVA
ASST PROF
SSCPS BHILAI

3. Thesearethedrugswhichusuallyalkaline
substancesandusedforneutralizingexcessacidin
thestomachofpatientssufferingfromHyper-
chlorhydria(hyperacidity).

4. It should be absorbable or cause systemic alkalosis.
Ability to raise thepHof the stomach to values in the range
ofpH3-4.5.
ability to maintain the desiredpHfor an adequate length of time.
It should not cause constipation.

5. SYSTEMIC (ABSORBABLE) ANTACID : e.g. Sodiumbicarbonate
NON SYSTEMIC(NON ABSORBABLE)ANTACID: Further classified
as
a.Aluminiumcontainingantacids:e.g. Aluminium hydroxide,
Aluminium phosphate, Basic aluminium carbonate.
b.Calciumcontainingantacids:e.g. Calcium carbonate, tribasiccalcium
phosphate.
c. Magnesium containing antacids: e.g. magnesium carbonate,
magnesium citrate , magnesiumhydroxide.
d.Combinationantacidpreparation:e.g.Aluminiumhydroxidegeland
magnesiumhydroxide.

6. SODIUMBICARBONATE :NaHCO
3 Mol wt -84.01
It contain not less than 99% not more than 100.5% of NaHCO3
.
SYNONYM -Sodium hydrogen carbonate, Baking soda , Mithasoda
PREPARATION :
2NaOH+CO
2
→Na
2CO
3+H
2O
Na
2CO
3+H
2O+CO
2→2NaHCO
3
PROPERTIES:Occurs as whitecrystaline or amorphous powder
saline taste. Freely soluble in water bt practicaly insoluble inalcohol
USES: It is mainly used as an electrolyte replenisher. it is mainly used
for its acid neutralizing properties , Antacid .

7. Aluminium hydroxidegel-Al(OH)
3 Mol wt 77.7
It is aqueous white viscous suspension of hydrated aluminium oxide having
varying amount of basic aluminium carbonate. Contain not less than 3.5% and not
more than 4.4 % w/w of aluminiumoxide.
SYNONYM -Aluminium hydrated powder
PREPARATION :
Aluminium chloride is treated with Ammonium hydroxide then pptaluminium
hydroxide is formed
AlCl
3+ 3NH
4OH  Al(OH)
3+ 3NH
4Cl
PROPERTIES : White viscous suspension. A clear liquid gets separated
when it is kept standing for some time. Al (OH)
3 gel gives astringent AlCl
3
when react with gastric HCl. Nausea, Vomiting andconstipation.
USES: Very effective slow acting antacid. Not absorbed in
alimentary canal and not produce carbon dioxide. Widely used in
intestinal toxemiaand hyperchlorhydria. Dos not cause gastric
alkalosis

8. CALCIUM CARBONATE -CaCO
3Mol wt –100.
SYNONYM Precipitated chalk pptcalcium carbonate
PREPARATION
Alternatively, calcium carbonate is prepared fromcalcium oxide. Water is added
to givecalcium hydroxidethencarbon dioxideis passed through this solution to
precipitate the desired calcium carbonate, referred to in the industry as
precipitated calcium carbonate
CaO+ H
2
O → Ca(OH)
2
Ca(OH)
2
+ CO
2
→ CaCO
3
↓ + H
2
O
PROPERTIES : It is a white odourless tasteless microcrystalline powder
USES : It is used as fast actingantacid , In calcium deficiency , It is used as
Dentrifrices

9. MAGNESSIUM CARBONATE –MgCO
3 Mol wt -84.03
It is hydrated basic magnessium carbonate containing 40-50% of magnessium oxide
SYNONYM -Magnesium carbonate
PREPARATION
Magnesium carbonatecan bepreparedin laboratory by reaction between any
solublemagnesiumsalt and sodium bicarbonate:
MgCl
2(aq) + 2NaHCO
3(aq) →MgCO
3(s) + 2NaCl(aq) + H
2O(l) + CO
2(g)
PROPERTIES : It is a light white friable mass or as bulky white powder , odourless ,
Practically insoluble in water and alcohol it exist in two forms heavy and light form
USES: It is used as antacid , It is used as Pharmaceutical aid

10. COMBINATION ANTACID
Preparations:
Aluminiumhydroxidemagnesiumcarbonatecodriedgel:Itisaco
precipitateofaluminiumhydroxideandmegnesiumcarbonateto
containcriticalproportionofwaterforantacidactivity.
Simecotablets:containaluminiumhydroxidemagnesiumcarbonate
codriedgel(282mg),magnesiumhydroxide(85mg)andactivated
dimethicone(25mg)
AluminiumhydroxidegelMagnesiumtrisilicatecombination:Thisisa
oneofmorecommoncombination.Ithaslaxative,constipativeand
protective
Calciumcarbonatecontainingantacidmixture:Calciumcarbonate
withaluminiumhydroxidegelyieldproductwhichhaverapidonsetwith
prolongedaction.
Magaldrate

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