Gastrointestinal agents

Viewers can get the thorough knowledge about Inorganic drugs used as Gastrointestinal Agents.

1. GASTROINTESTINAL AGENTS
REVATHI.G
M.PHARM
PHARMACEUTICAL CHEMISTRY
ASSISTANT PROFESSOR,SVCP

2. Gastrointestinal Agents or GIT tract
➢OneoftheVitalorganPresentinthebody.
➢Responsiblefor;
1.Consuminganddigestingfoodstuffs,
2.Absorbingnutrientsandexpellingwaste.
➢EffectedbyEnzymaticbreakdownofcomplexfoodmoleculesinto;
➔Monosaccharides,Aminoacidsandglycerides.
➢DysfunctionofanyoneoftheGITsystem→Humanillness
➢Thetractconsistsofthestomachandintestines,andisdividedintotheupperandlower
Gastrointestinaltracts.

3. GIT AGENTS
Agentsusedtotreatgastrointestinaldisturbanceareknownasgastrointestinalagents.
Forthetreatmentofgastrointestinaldisorderofmoreseriousconditions,thevariousinorganic
agentsusedtotreatGITdisordersinclude/classififedas:
1.Acidifying agents and antacids →Products for altering gastric pH
2.Protectives →intestinal inflammation
3.Adsorbents →intestinal toxins
4.Saline cathartics or laxatives →constipation

4. CONTENTS
ACIDIFYING AGENTS ANTACIDS PROTECTIVES AND
ADSORBENTS
SALINE CATHARTICS
Dilute Hydrochloric Acid Sodium Bicarbonate,
Aluminium Hydroxide,
Aluminium Phosphate,
Calcium Carbonate,
Magnesium Carbonate,
Magnesium Oxide,
Magnesium Trisilicate
Bismuth Sub carbonate
and
Kaolin
Sodium Potassium
Tartarate
Magnesium Sulphate

5. ACIDIFYING AGENTS
•InDigestionofFood→importantconstituentofgastricjuicearePEPSIN(proteolyticenzyme)andHydrochloric
acid(Hcl)
•Alwaysthereisasmallquantityofgastricjuicepresentinstomach,evenitcontainsnofood→Fastingjuice
•Pepsin→mosteffectiveinacidicenvironment(pH2.0)andbecomesinactiveathigherpH(alkaline)
•Hydrochloricacidpresentingastricjuiceactsas;
➢Acidifiesfoodandstopstheactionofptyalin
➢Killsmicrobeswhichactsagainsttoourbody
➢Providesacidenvironmentneededforeffectivedigestionbypepsin
•Pepsinogens→activatedtopepsinbyHcl

6. HCL
Secreted By Oxyntic (parietal) Cells
Secretion under the control of;
Acetylcholine Histamine Gastrin

7. GASTRIC ACID SECRETION
GOVERNED BY
HISTAMINE MUSCARINIC GASTRIN
Mast cells post ganglionic G cells
vagal neurons

8. GASTRIC ACID SECRETION

9. PARIETAL CELLS(OxynticCells)
➢Are EpithelialCells
➢Secrete Hydrochloric Acid (Hcl) And Intrinsic Factor.
➢Located In TheGastricGlands
➢Found In Lining Of The FundusAnd Body Regions Of TheStomach.
LINK→HTTPS://YOUTU.BE/ZADJ0K0WAFY
BILE CANALICULUS (Bile Capillaries)
➢Is A Thin Tube That Collects Bile Secreted By Hepatocytes.
➢BileCanaliculiEmpty Into A Series Of Progressively
➢Larger Bile DuctulesAnd Ducts,
➢Which Eventually Become Common Hepatic Duct

10. ACHLORHYDRIA
Patients Suffering From Achlorhydria
1. Respond to stimulation by Histamine phosphate
•( Release of gastric acid Increases)
2. Lack of gastric HCleven after stimulation of Hp
•10% w/w Dil.HClrecommended to releivefrom achlorhydria
•Note→Hypochlorhydria–low gastric acid content

12. DEFINITION
•ChemicalSubstancesWhichRemoveTheExcessAcidAndRaisethepHToAnAppropriate
LevelInStomachAreCalled“Antacid”.
•AntacidsAretheDrugsactsasabasicsaltUsedToNeutralizetheHydrochloricAcidSecretedin
theStomachInGastricJuice.
•TheyraisethepHofthegastriccontentstoabove3.5andgivethesymptomaticreliefofpain
(ingastricandduodenalulcers)
•Byloweringtheacidityandconsequentlyrelievingthemusclespasm.
•Theydothisbyactingasweakbases

13. ANTACIDCOMPOUNDS
Antacidsareweakbases→used to neutralize excessstomachacid
Mostantacids areweakinorganicbases
Commonexamples include;
1. SODIUM BICARBONATE
2. ALUMINIUM HYDROXIDE GEL
3. ALUMINIUM PHOSPHATE
4. CALCIUM CARBONATE
5. MAGNESIUM CARBONATE
6. MAGNESIUM TRISILICATE
7. MAGNESIUM OXIDE AND COMBINATION OF ANTACID PREPARATIONS

14. REACTIONOFANTACID
AntacidsreactwithHCl inthestomach
Somecommon antacidreactions include:
CaCO
3 + 2 HCl →CaCl
2 + H
2O + CO
2
NaHCO3 + HCl →NaCl + H
2O + CO
2
Al(OH)3 + 3 HCl →AlCl
3 + 3 H
2O
Mg(OH)2 + 2 HCl →MgCl
2 + 2 H
2O
MgO + 2 HCl →MgCl
2 + H
2O

15. MECHANISM OF ANTACID
•Antacidsperformaneutralizationreaction,inthestomachandbyinhibitingpepsin,whichisaproteolytic
enzyme.
•Theybuffergastricacid,raisingthepHtoreduceacidityinthestomach.
•Whengastrichydrochloricacidreachesthenervesinthegastrointestinalmucosa,theysignalpaintothecentral
nervoussystem.Thishappenswhenthesenervesareexposed,asinpepticulcers.
•Thegastricacidmayalsoreachulcersintheesophagusortheduodenum.
•Link→https://youtu.be/d3X0gurRdhg

16. ANTACID MECHANISM

17. HOW ANTACID WORKS ?

18. CAUSES OFEXCESSIVERELEASEOFACIDSINTHE STOMACH

19. AVAILABLE ANTACIDS
SUSPENSION

20. SOME FAMOUS BRANDS OF ANTACIDS
1.ALKA-SELTZER–NAHCO
3
AND/ORKHCO
3
2.EQUATE–AL(OH)
3
ANDMG(OH)
2
3.GAVISCON–AL(OH)
3
4.MAALOX(LIQUID)–AL(OH)
3
ANDMG(OH)
2
5.MAALOX(TABLET)–CACO
3
6.MILKOFMAGNESIA–MG(OH)
2
7.PEPTO-BISMOL–HOC6H4COO
8.PEPTO-BISMOLCHILDREN’S–CACO
3
9.ROLAIDS–CACO
3
ANDMG(OH)
2
10.TUMS–CACO
3
11.MYLANTA

21. USES OF ANTACIDS
ItBringDownthePercentageOfAcidityInOurStomachAndPreventMucusLiningInThe
Stomach.
ItPreventFromHeartBurn(AcidFromStomachRisingIntoEsophagus)thatCanToOurStomach
Lining.
ItAlsoPreventFromTheUlcer(damageToLiningOfStomachWall,ResultingInLossOfTissues
AndInflammation).

22. SIDE EFFECTS
MagnesiumCompoundsMayCauseDiarrhea
AluminumCompoundsMayCauseConstipationAndTheyAlsoMayInterfereWithThe
AdsorptionOfPhosphatesInTheFormationOfBones.ThisIsMoreLikelyToBeTrueIfThey
AreTakenForAnExtendedPeriodOfTime
CarbonatesMayGenerateCarbonDioxideLeadingToBloatingAndFlatulence.
CalciumCompoundsContainingMayAlsoIncrease Calcium Output In The Urine, Which
Might Be AssociatedWithKidneyStones.
Sodium: Increased Intake Of Sodium May Be DeleteriousForArterialHypertension,
HeartFailure AndManyRenalDiseases.

23. WHOCANNOTTAKEANTACID
•PatientWithKidneyFailureOrHeartBurnDiseasesSodium Bicarbonate Has High Sodium
Content And Is Not Appropriate For People Who Are On Salt Restricted Diet Or Have
Congestive HeartFailureHighBloodPressureOrKidneyProblem.In Pregnant If A Lady Is
Pregnant Antacid Are SafetousFor Heart Burn SymptomsButDo NotUseAntacid.

24. INDICATIONSWHENWE TAKEANTACID
WhenHeartBurnIsThereThenWeTakeAntacidToReduceTheHeartburn.
TreatmentWithAntacidsAloneIsSymptomaticAndOnlyJustifiedForMinorSymptoms.
TheUtilityOfManyCombinationsOfAntacidsIsNotClear,AlthoughTheCombinationOf
MagnesiumAndAluminiumSaltsMayPreventAlterationOfBowelHabits.
ATypicalFeelingOfRestlessness.
Indigestion.
FeelingOfNausea(WantingToThrowUp)AndActualVomiting.

25. CLASSIFICATION OF ANTACIDS
Non-
systemic
•Directly neutralize the acid in stomach and give
relief to gastric and duodenal ulcers.
Aluminumhydroxide gel,
AluminumMagnesium carbonate,
Magnesium phosphate & trisilicate,
Calcium carbonate
Magnesium oxide
Systemic
•Absorbedfrom gut into blood circulation →cause alkalosis.
•Also called systemic alkalisers
•Injection to relieve acidosis in blood, especially diabetic coma
Sodium bicarbonate

26. COMBINATION OF ANTACID
•3 complications are seen, when antacids used;
1.Exerts an action on the bowel with some mild laxative (MgOH) & constipation Al(OH)
3effect
2.If the Cation (metallic ion) is absorbed →systemic alkalosis (NaHCO
3) produced
3.Calcium ions →hypercalcemia & mg and Al →precipitation of PO
4in GIT and Phosphorous gets
depleted
4.Affects the absorption of other drugs which are administered along with antacids such as
anticholinergics and antibiotics, due to its adsorption by antacids →alter pH and delays absorption
5.Dyspepsia →gas formation in gut –use of methylpolysiloxane( dimethicone / simethicone )
necessary.
6.In order to minimize this defects →combination of antacids are to be used
(MgOH) + Al(OH)
3combination →Balancing the laxative and constipation effect

27. ANTACID COMBINATIONS IN CLINICAL USE
Magnesium And Aluminium
Hydroxide ( Magaldrate )
Magnesium And Aluminium
Hydroxide, Dimethicone ( Dioval
Forte Tablets )
Magnesium And AluminiumHydroxide,
Methylpolysiloxane(GelusilMps)
AluminiumHydroxide Gel And
Magnesium Trisilicate (Gelusil)
AluminiumHydroxide Gel,
Magnesium Hydroxide And
Magnesium Trisilicate (GelusilM)
Magnesium And Aluminium
Hydroxide, Methylpolysiloxane,
sodium Carboxy Methyl Cellulose
(DigeneGel)

28. SYSTEMIC ANTACIDS
1. SODIUM BICARBONATE (NaHCO
3)
❑Synonym : Baking soda
❑Molecular Formula : NaHCO
3
❑Molecular weight : 84.01 gm
❑Category: Antacid
❑Standard: It contains 99 –100.5 % equivalent of sodium bicarbonate calculated with reference to
dried compound.
❑Preparation: LABORATORY METHOD
I) It is prepared by passing CO
2gas through NaOH solution2 NaOH+ CO
2
Na
2
CO
3
+ H
2
O
Sodium hydroxide carbondioxide sodium carbonate water

29. II)Further, Addition Of CO
2Produces Sodium Bicarbonate Will Precipitate Out Of Solution
❑INDUSTRIAL METHOD
➢SOLVAY PROCESS
✓Brine Solution (Nacl) Is Saturated With Ammonia(To Remove Impurities).
✓The Solution Is Filtered, CO
2Is Passed Through The Solution.
✓Precipitate→Filtered And Dried. Na
2
CO
3
+ H
2
O+ CO
2 2NaHCO
3
sodium carbonatewatercarbondioxide Sodium bicarbonate
H
2O + CO
2→H
2CO
3
NH
3+ H
2CO
3→NH
4HCO
3
NaCl + NH
4HCO
3→NaHCO
3+ NH
4Cl

30. ❑Physical properties:
✓Its is a white, odourlessand crystalline powder
✓Stable in dry air and Saline Taste.
✓In moist air →decomposes to sod.co
3, water, co
2
✓Soluble in water
✓Insoluble in alcohol
❑Chemical Properties:
1.When heated with water →loses water and carbondioxideand forms carbonate

31. 2. CO
2is again liberated when it is heated with any acid
3.Reacts with mercury chloride →forms Reddish brown precipitate of mercury oxide (HgO)NaHCO
3
+ HCl

= NaCl + H
2
O + CO
2
Sodium bicarbonate Hydrochloric acid Sodium chloride water Carbondioxide HgCl
2+2NaHCO
3
Hg(HCO
3
)
2 +2NaCl
Hg(HCO
3
)
2
HgO+
H
2
O+
CO
2
Mercury chlorideSodium bicarbonate Mercury bicarbonate Sodium chloride
Mercury bicarbonate Mercury oxide Water Carbondioxide

32. ❑Test For Identity:
Solution of a substance + CO
2free water +Phenolphthalein
Pale pink colouris produced ( due to alkalinity of NaHCO
3)
On heating
Evolution of CO
2gas
Solution becomes Red ( due to formation of Na
2CO
3)

33. ❑Test For Purity:
✓Arsenic
✓Calcium
✓Heavy metals
✓Chloride
✓Sulphate
❑Assay :
Acid -base titration
Weighed amount is dissolved in water + titrated with sulphuricacid using methyl orange as indicator.
2NaHCO
3+ H
2SO
4→ Na
2 SO
4+ 2CO
2+ 2H
2O
❑Storage condition :
✓ It should be stored in a well –closed container.
✓ Since, it slowly decomposed when exposed to moist air

34. ❑Dosage:
1 to 4 gm per day
❑Medicinal And Pharmaceutical Uses:
✓Used As An Antacid
✓Used In Systemic Acidosis, Especially In Diabetic Coma
✓Used As A Electrolyte Replinisher
✓Used As Local ApplicationFor Burns, Insect Bites Etc.
✓Used As A Constituent In Ear Drops To Soften And Remove Wax.

35. NON -SYSTEMIC ANTACIDS
1. ALUMINIUMHYDROXIDE GEL
❑Description:
✓It is an aqueous suspension of hydrated aluminium oxide together with varying amounts of basic
aluminium carbonate.
✓It contains aluminium oxide, glycerin, sucrose or saccharin as a sweetening agent, peppermint oil as a
flavouring agent and sodium benzoate as a preservative.
❑Synonym : Aluminicacid
❑Molecular Formula : Al(OH)
3
❑Molecular weight : 78 gm
❑Category: Antacid
❑Standard: It contains not less than 3.5 % and not more than 4.4 % w/w Al
2O
3

36. ❑Preparation:
1.Prepared by the reaction of an aluminiumsulphate or aluminiumchloride with sodium carbonate or
sodium bicarbonate.
2.The precipitate of aluminiumhydroxide is collected, washed and resuspended in water and finally
homogenized.
3Na
2CO
3+ 3H
2O→ 3NaHCO
3+ 3 NaOH
Alcl
3+ 3NaOH+ H
2O → 3 NaCl + Al(OH)
3. 3H
2O
2NaHCO
3→ Na
2CO
3+ H
2O + CO
2

37. HOW TO PREPARE ALUMINIUMHYDROXIDE ?

38. ❑Physical Properties :
1. It is a white viscous suspension.
2. A clear liquid gets separated when it is kept standing for sometime.
3. pH between 5.5 to 8.0
4. Amphotericin nature and
5. Dissolves readily in acids or alkalis →forming aluminiumsalts and aluminates
❑Chemical properties:
❑When heated strongly →decomposes into Aluminium oxide and water
❑It reacts with HCl →forms Aluminium Chloride
Al(OH)
3+ 3HCl = AlCl
3+ 3H
2O

39. ❑Assay:
Complexometric titration
❑Test for Purity
✓pH
✓Arsenic
✓Heavy metals
✓Chloride
✓Sulphate
❑Storage
Stored in a tightly closed container in a cool place. Avoid freezing.
❑Uses:
1. As an antacid.
2. Since aluminiumsalts produce constipation, and are therefore generally administered along with magnesium salts
to counteract this effect.
3. Used in cases of acute hyper acidity
4. Acts as a Protective in treating Peptic ulcers.

40. 1. DRIED ALUMINIUMHYDROXIDE GEL
❑Synonym : Aluminicacid
❑Molecular Formula : Al(OH)
3
❑Molecular weight : 78 gm
❑Category: Antacid
❑Standard :It contains not less than 47% and not more than 60% of Al
2O
3
❑Properties:
✓White, light, amorphous powder
✓Odourlessand tasteless
✓Consists of;
1. hydrated aluminiumoxide
2. small quantities of basic aluminiumcarbonate and bicarbonate
✓Insoluble in water and alcohol
✓Soluble in mineral acids

41. ❑Chemical properties:
❑When heated strongly →decomposes into Aluminium oxide and water
❑It reacts with HCl →forms Aluminium Chloride
Al(OH)
3+ 3HCl = AlCl
3+ 3H
2O
❑Assay:
Complexometric titration
❑Test for Purity
✓pH
✓Arsenic
✓Heavy metals
✓Chloride
✓Sulphate
❑Storage
Stored in a tightly closed container

42. ❑Medicinal and Pharmaceutical Uses:
1. As an antacid.
2.Used in cases of acute hyper acidity
3. Acts as a Protective in treating Peptic ulcers.
4. Since aluminiumsalts produce constipation, and are therefore generally administered along with
magnesium salts to counteract this effect.

43. 3. ALUMINIUM PHOSPHATE ( AlPO
4)
❑Synonym :Driedaluminumphosphate gel
❑Molecular Formula :AlPO
4
❑Molecular weight :122gm
❑Category: Antacid
❑Standard: It consistsmainly 80% of hydrated aluminiumortho phosphate (AlPO
4).
❑Preparation:
1. By interaction between aqueous Aluminiumchloride and sodium phosphate
AlCl
3+ Na
3PO
4 AlPO
4 + 3NaCl

44. HOW HCLGETS LIBERATED ?

45. 2. Solution of dried dibasic sodium phosphate in water is added slowly to solution of AlCl
3→AlPO
4is formed
along with NaCl and HCl
3. HCl formed is neutralized by adding diluted ammonia.
Mixture is filtered and washed with water to free it from soluble salts
Sufficient water is added to get a gel with Con. About 4% AlPO
4
All the water is removed and product gets dried under suitable condition
To get a dried ALPO
4
AlCl
3.6H
2O + Na
2HPO
4= AlPO
4+ 2NaCl + HCl + 6H
2O
HCl + NH
4OH = NH
4Cl + H
2O

46. ❑PhysicalProperties:
1.Itisawhitepowderorsuspensionhavingfriableaggregates.
2.Insolubleinethanol,water,NaOHsolutions
3.SolubleinDilutemineralacids
3.Gel→pHbetween6.0to7.2
❑Chemicalproperties:
❑UndergoesAcidneutralizingcapacityisbasedonthereleaseoftrivalentphosphateionduetoits
Stronglybasicnature
AlPO
4 Al
+3
+ PO
4
-3

47. ❑Assay:
Complexometrictitration
❑Dosage:5–15ml(1teaspoonful–1tablespoon)
❑TestforPurity
✓Acidityandalkalinity
✓Arsenic
✓Heavymetals
✓Phosphate
❑Storage
Storedinawellclosedcontainer

48. ❑MedicinalandPharmaceuticalUses:
✓UsedasaMildslowactingantacidhavinghalftheacidneutralisingcapacityofaluminium
hydroxidegel
✓Itisbetterthanaluminiumhydroxidegelinthesensethatitdoesn’tinterferewiththeabsorption
ofphosphatesfromtheintestine

49. 4. CALCIUM CARBONATE (CaCO
3)
❑Synonym :Precipitated Chalk
❑Molecular Formula :CaCO
3
❑Molecular weight :100gm
❑Category: Antacid
❑Standard: It contains not less than 98% and not more than 100.5% CaCO
3
❑Preparation:
1. Prepared by mixing solution of calcium chloride and sodium carbonate
CaCl
2+ Na
2CO
3 CaCO
3+ 2NaCl

50. Reaction B/W Calcium Chloride And Sodium Carbonate

51. 2. Prepared by passing CO
2through lime water
❑PhysicalProperties:
1.Itisawhite,odourless,tastelessmicrocrystallinepowder
2.InsolublewaterandslightlysolubleinwatercontainingCO
2.
3.InSolubleinalcoholandsolubleinsomeacids
4.StableinAir
Ca(OH)
2+ CO
2 CaCO
3+ H
2O
Calcium hydroxide Carbondioxide Calcium carbonate

52. HOW CO
2PASSEDTHROUGH LIME WATER?

53. ❑Chemical properties:
It decomposes back to CaOand CO
2when heated beyond 83
0
c. Its solubility is enhanced in presence of CO
2
❑Assay:
Complexometric titration
❑Test for Purity:
✓Arsenic
✓Heavy metals
✓Chloride
✓Sulphide
✓Barium
CaCO
3+ H
2O+ CO
2 Ca(HCO
3)
2
CALCIUM CARBONATE CARBONDIOXIDE CALCIUM BICARBONATE

54. ❑Storage:
Is stable in air, it may be stored in a well closed container.
❑Medicinal and Pharmaceutical Uses
✓Used as fast acting non-systemic antacid
✓As a supplement for calcium deficiency
✓As Dentrificesdue to mild abrasive property and in cosmetics
✓As a precipitated chalk used in Tooth powder.
✓Also used in treatment of some forms of diarrhoea, due to its non-irritating nature.
✓Limestone→used in manufacture of cement, lime, washing soda and glass.

55. 5. MAGNESIUM CARBONATE (MgCO
3)
(Heavy and light magnesium carbonate)
❑Synonym : Mineral magnesite
❑Molecular Formula :MgCO
3.Mg(OH)
2.5H
2O (Heavy)OR MgCO
3.Mg(OH)
2.3H
2O (light)
❑Molecular weight :485gm
❑Category: Laxative
❑Standard: It is hydrated basic MgCO
3containing40-45%MgO
❑Preparation:
1. Is prepared by mixing hot solutions of MgSO
4and sodium carbonate
MgSO
4+ Na
2CO
3 MgCO
3+ Na
2SO
4

56. 2. Is Precipitated by the addition of sodium carbonate to an aqueous solution of a Mg salt and saturating it
with CO
2
MgCl
2+ 2NaHCO
3+ CO
2+ H
2O MgCO
3 2NaCl + 2H
2CO
3
Heavy magnesium carbonate -MgCO
3.Mg(OH)
2.5H
2O (40-45% OF CaO)
Hot solutions of
Magnesium sulphate (125 parts) + Sodium carbonate (150 parts) in Water (250 parts)
Mixed
Evaporated →dryness
Dried Residue →treated with water
Insoluble carbonate is filtered
Washed and dried in oven

57. Light magnesium carbonate -MgCO
3.Mg(OH)
2.3H
2O (40-45% OF CaO)
Mixing solutions of
Magnesium sulphate (125 parts) + Sodium carbonate (150 parts) in Water (1000 parts)
Mixed
Boiled for 15 Minutes
Precipitate is obtained
filtered
Washed and dried in oven

58. MAGNESIUM CARBONATE PREPARATION

59. ❑PhysicalProperties:(Heavy&LightMgCO
3)
1.HydratedMgCO
3→contains40-45%ofMgO
2.White,odourlesspowderorlight,whiteandfriablemasses
3.InSolubleinwaterandalcoholbutdissolveindiluteacids
4.StableinAir
❑Chemical properties:
1. It reacts with dilute acids →strong effervescence. At 700
0
C, converted into MgO
MgCO
3 MgO + CO
2

60. 2. When heated to redness →give MgO
3[MgCO
3.Mg(OH)
2.5H
2O] 4MgO + 3CO
2+ 6H
2O
❑Assay:
Complexometric titration
❑Test for Purity:
✓Arsenic
✓Heavy metals
✓Chloride
✓Sulphide
✓Copper and Lead

61. ❑Storage:
Stored in a well closed container.
❑Medicinal and Pharmaceutical Uses
✓Used as a Cathartic and laxative
✓Also used in food additive, in tooth and face powders
✓Used as a mild non-systemic Antacid

62. 6. MAGNESIUM TRISILICATE
❑Synonym : Epsom salt, Hydrated magnesium silicate
❑Molecular Formula :2MgO.3SiO
2.3H
2O
❑Molecular weight :261gm
❑Category: Adsorbent and Antacid
❑Standard: It is hydrated basic MgCO
3containing40-45%MgO
❑Preparation:
1. Is prepared by mixing hot solutions of MgSO
4and sodium carbonate
2MgSO
4+ 4NaSiO
2 + excess 3H
2O 2MgO.3SiO
2.3H
2O + 2Na
2SO
4 + SiO
2

63. HOW MAGNESIUM TRISILICATE FORMULATED ?

64. ❑PhysicalProperties:
1.Odourless,tasteless,whitegrainypowder
2.Slightlyhygroscopicinnature
3.Insolubleinwaterandalcohol
❑ChemicalProperties :
1. When Treated With any acid such as dil.HCl→forms MgCl
2and gelatinous trisilicic
acid
Mg
2Si
3O
8+ 4HCl = 2MgCl
2+ H
4Si
3O
8
Magnesium trisilicate Trisilicicacid

65. 2. It neutralises gastric acid
MgO + 2H
3O Mg(OH)
2+ 2H
2O
MgO + 2HCl MgCl
2+ H
2O
❑Assay:
Complexometric titration
❑Test for Purity:
✓Arsenic
✓Heavy metals
✓Chloride
✓Sulphide
✓Copper and Lead

66. ❑Dose:
I gm four times a day
❑Storage:
Stored in a well closed container.
❑Medicinal and Pharmaceutical Uses
✓Used as an antacid and adsorbent.
✓Reduces gastric pain and hyperacidity
✓Used in larger doses to induce diarrhoea
✓Due to presence of Silicon dioxide, it acts as a protectant for gastric mucosa in ulcers.

67. 7. MAGNESIUM OXIDE (MgO)
❑Synonym : Magnesia
❑Molecular Formula :MgO
❑Molecular weight :40gm
❑Category: Osmotic laxative and dentrifice
❑Standard: Not less than 98%MgO
❑Preparation:
1. Is prepared by gently heating the magnesium carbonate
MgCO
3 MgO + CO
2
2. When light carbonate is heated →redness, MgO is formed
3MgCO
3. Mg(OH).3H
2O 4MgO + 3CO
2+4H
2O

68. ❑PhysicalProperties:
1.Verylight,bulky,whitepowder→lightMgO,Densemass→heavyMgO
2.Odourless,slightlyalkalinetaste
3.Practicallyinsolubleinwater
4.Dissolvewithdiluteacids→slighteffervescence
5.Whenexposedtoair→absorbsmoistureandCO
2

69. ❑ChemicalProperties :
1. Is soluble in carbonic acid solution
MgO + H
2O + 2CO
2 Mg
+2
+ 2HCO
-
3
2. At high temperatures, it reacts with carbon to form Magnesium carbide
CaC
2+ MgO MgC+ CaO+ C
3. MgO reacts with acid →form salts
MgO + 2HCl MgCl
2+ H
2O
❑Assay:
Complexometric titration

70. ❑Test for Purity:
✓Arsenic
✓Heavy metals
✓Iron
✓Sulphide
✓Copper and Lead
❑Storage:
Stored in a well closed container.
❑Medicinal and Pharmaceutical Uses
•Antacid And Osmotic Laxative
•Used As An DentrificeAnd Food Additives

71. COMBINATION OF ANTACID PREPARATIONS
•COMBINATIONS OF ANTACID
•PREPARATIONS
•ANTACID PREPARATIONS ARE FORMULATED WITH ONE MORE THAN ONE ANTAC ID AS COMBINATIONS TO
COUNTERACT THE SIDE EFFECT OF ONE BY ANOTHER OR TO BE USED FOR S PECIFIC CONDITIONS.
•(I) ALUMINIUM HYDROXIDE GEL –MAGNESIUM HYDROXIDE COMBINATION.
•PREPARATION: AVAILABLE AS ORAL SUSPENSION AND TABLETS.
•ADV: SINCE ALUMINIUMSALTS CAUSES CONSTIPATION, THIS EFFECT IS BALANCED BY LAXATIVE EFFECT OF
MAGNESIUM.
•(II) SIMETHICONE CONTAINING ANTACIDS
•IT IS FORMULATED ALONG WITH ALUMINIUMHYDROXIDE GEL AND MAGNESIUM HYDROXIDE.
•IT IS AVAILABLE AS ORAL SUSPENSION AND TABLET.
•ADVANTAGE: SIMETHICONE RELIEVES FLATULENCE.
•(III) ALUMINIUM HYDROXIDE GEL –MAGNESIUM TRISILICATE COMBINATIO N
•IT IS AVAILABLE AS ORAL SUSPENSION AND TABLET.
•ADVANTAGE:
•MAGNESIUM TRISILICATE HAS PROTECTIVE EFFECT.

72. Magnesium And Aluminium
Hydroxide ( Magaldrate )
Magnesium And Aluminium
Hydroxide, Dimethicone ( Dioval
Forte Tablets )
Magnesium And Aluminium Hydroxide,
Methylpolysiloxane (Gelusil Mps)
Aluminium Hydroxide Gel And
Magnesium Trisilicate (Gelusil)
Aluminium Hydroxide Gel, Magnesium
Hydroxide And Magnesium Trisilicate
(Gelusil M)
Magnesium And Aluminium Hydroxide,
Methylpolysiloxane, sodium Carboxy
Methyl Cellulose (Digene Gel)

73. Magnesium And AluminiumHydroxide
( Magaldrate )
Magaldrate →product of chemical combination of aluminiumhydroxide and magnesium
hydroxide along with the sulphates of aluminiumand magnesium
❑Synonym : MAGALDRATUM
❑Molecular Formula :Al
5Mg
10(OH)
31(SO
4)
2,xH
2O
❑Molecular weight :164gm
❑Category: Antacid
❑Standard: Not more than 100.5 %and Not less than 90%Al
5Mg
10(OH)
31(SO
4)
2,xH
2O
❑Assay: Potentiometric titration

74. ❑PhysicalProperties:
1.White,crystallinepowder
2.Odourless,slightlyalkalinetaste
3.Practicallyinsolubleinwaterandwater
4.Dissolvewithdiluteacids
❑Test for Purity:
✓Arsenic
✓Heavy metals
✓Iron
✓Sulphide
✓Copper and Lead

75. ❑Storage:
Stored in a well closed container.
❑Medicinal and Pharmaceutical Uses
•Antacid
•Magaldrate used in the formulation of magaldrate oral suspension and oral tablet