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Pharmacy!!!!Pharmaceutical powder
chapter

1. PHARMACEUTICAL
POWDERS
Prepared By. SUMANA
Dept. of. Pharmaceutics
SDCP, Mangalore

2. POWDERS
•Apharmaceuticalpowderisamixtureoffinelydivideddrugandchemicalsindryform.
•Thesearesoliddosageformofmedicamentwhichismeantforinternalandexternaluse.
•Theyareavailableincrystallineoramorphousform.
ADVANTAGES
•Morestablethanliquiddosageforms
•Moreconvenienttoswallowthantabletorcapsules
•Canbepreparedintogranulesforuseinpreparingtabletsandorreconstitutedtoliquidform
•Rapidtherapeuticeffectduetohighsurfacearea
•Usefulforbulkydrugswithlargedose
•Chancesofincompatibilityarelesscomparedtoliquiddosageforms.
•Powdersaremoreeasytotransportthantheliquiddosageform.
•Theonsetofactionofpowdereddrugisrapidascomparedtoothersoliddosageform.E.g.tablets,capsules
•Children&elderlypatientscaneasilytakepowdereddrugassuchorbydispersingitinwaterorotherliquid.
•Economicaldosageforms(minimaluseofmachinery/specialtechniques}
2Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

3. DISADVANTAGES
•Drugshavingbitter,nauseousandunpleasanttastecan’tbedispensedinpowderedform.
•Deliquescentandhygroscopicdrugscan’tbedispensedinpowderform
•Drugswhichgetaffectedbyatmosphericconditionsarenotsuitablefordispensinginpowderforms.
•Thedispensingofpowderistimeconsuming.
MIXINGOFPOWDERS
1.SPATULATION
2.TRITURATION
3.GEOMETRIC DILUTION
4.SIFTING
5.TUMBLING
3
Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

4. 1.SPATULATION
•Mixingofpowdersdonebymovementofspatulathroughoutthepowdersonasheetofpaperoron
aporcelaintile.
•Thismethodisusefulinmixing
Smallamountofpowder
Solidsubstancesthatliquefyorformeutecticmixtures,wheninclose&prolongedcontactwith
oneanother(sinceverylittlecompactionoccurs]
•Thismethodisnotsuitableforlargequantitiesofpowderorpowderscontainingoneormore
potentsubstances(becausehomogenousblendingmaynotoccur}
4
Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

5. 2. TRITURATION
•It is used to reduce particle size as well as to mix powders.
•Apparatus
•Porcelain mortar & pestle (for size reduction as well as mixing}
•Glass mortar & pestle (for chemicals that stains the porcelain surface}
•Glass mortar cleans more readily after use.
5
Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

6. 3.GEOMETRIC DILUTION
•Thismethodisusedwhenpotentsubstancesaretobemixedwithalargeamountofdiluent.
•Thepotentdrug&equalquantityofdiluentisplacedonamortar&thenslightlytriturated.
•2ndportionofdiluentinequalquantitytotheabovepowdermixtureisaddedtomortar&triturated.
•Theprocessiscontinued,addingdiluentinequalquantitiestothepowdermixtureinthemortarateachstep;untilallthe
diluentisincorporated.
•Forexample;Potentdrug-100mg
Lactose(diluent)-900mg
100mgofpotentdrug+100mgLactose-200mgofmixture
200mgofmixture+200mgoflactose-400mgofmixture
400mgofmixture+400mgofLactose-800mgofmixture.
800mgofmixture+remainingportionofLactose(200mg)=1000mgofmixture
6

7. 4.SIFTING
•Powdersaremixedbypassingthroughsifters.
•Thisresultsinalightfluffyproduct&generallynotacceptableforincorporationofpotentdrugsintodiluentbase.
5.TUMBLING
•Itistheprocessofmixingpowdersinalargecontainersrotatedbyanelectricmotor.
•TheseblendersareusedinIndustriesaslargevolumepowdermixers.
7Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

8. CLASSIFICATION OF POWDERS
•{Based on method of dispensing}
1.BULK POWDERS FOR INTERNAL USE
2.BULK POWDERS FOR EXTERNAL USE
3.SIMPLE & COMPOUND POWDERS FOR INTERNAL USE
4.POWDERS ENCLOSED IN CACHETS & CAPSULES
5.COMPRESSED POWDERS (TABLET TRITURATES)
8
Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

9. 9Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

10. BULKPOWDERS
•Powdersaredispensedinbulk,whenaccuracyofdosageisnotimportant.
•Bulkpowdercontainsseveraldosesofpowder.
•Theyaresuppliedinwide-mouthedcontainersthatpermitseasyremovalofaspoonfulpowder.
•Thenonpotentsubstanceswhicharesuppliedinbulkareantacidsandlaxativesetc.
1.BULKPOWDERFORINTERNALUSE
•Theyaremixtureoffinelydivideddrugsandorchemicalsinadryformthatmaybeintendedforinternaluse(oral
powders)
Types:
a)Oralpowder
b)Powderspray
e)Drypowderinhalers
d)Effervescentpowders
10Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

11. Example:
A)Send25.0gofRhubarbpowderB.P.C.(Gregory’sPowder)
R
x
Rhubarb,inpowder-250.0g
Lightmagnesiumcarbonate-325.0g
Heavymagnesiumcarbonate-325.0g
Ginger,inpowder-100.0g
Makeapowder
Direct:0.5to5.0gtobetakentwiceaday.
Method:Powderallingredients.Weigh&mixtheminascendingorderoftheirweight.Transferthe
powderinawidemouthbottle&dispense.
11Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

12. B)Send 50.0 g of compound bismuth powder
R
x
Calciumcarbonate-75.0g
Heavymagnesiumcarbonate-75.0g
Sodiumbicarbonate–25.0g
Bismuthcarbonate–25.0g
Makeapowder
Direct:5gtobetakentwiceaday.
Method:Powderedallingredients.Weigh&mixtheminascendingorderoftheirweight.Transfer
thepowderinawidemouthbottle&dispense.
12Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

13. 2.BULKPOWDERSFOREXTERNALUSE
•Bulkpowdersforexternalusecontainnon-potentmedicaments.
•Thesepowdersaresuppliedincardboard,glassorplasticcontainers,which
oftendesignedforthespecificmethodofapplication.
•Thebulkpowdersforexternaluseare:
A)Dustingpowders
B)Insufflations
C)Snuffs
D)Dentifrices
13Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

14. A.DUSTINGPOWDERS
•Theseareusedexternallyforlocalapplicationnotintendedforsystemicaction.Thedesiredcharacteristicsofpowdersinclude
a) Homogeneity
b) Non-irritability
c) Freeflow
d) Goodspreadabilityandcoveringcapability.
e) Adsorptionandabsorptioncapacity.
f) Veryfinestateofsubdivision,and
g) Capacitytoprotecttheskinagainstirritationcausedbyfriction,moistureorchemicalirritants.
•Dustingpowdersusuallycontainsubstancessuchaszincoxide,starchandboricacidornaturalmineralsubstancessuchas
kaolinortalc.
•Dustingpowdersaremeantforexternaluse&aregenerallyappliedinaveryfinestateofsubdivisiontoavoidlocalirritation.
•Hence,dustingpowdersshouldbepassedthroughsieveno.80toenhancetheireffectiveness.
•Dusting powders are of 2 types:
a) Medical dusting powders
b) Surgical dusting powders
14Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

15. MEDICALDESTINGPOWDERS
•Usedmainlyforsuperficialskinconditions.
•Mustbefreefrompathogenicmicroorganisms.
SURGICALDUSTINGPOWDERS
•Usedinbodycavities,onwounds&onumbilicalcordsofinfants.
•Thesemustbesterilizedbeforeuse.
Methodofpreparation
•Dustingpowdersaregenerallypreparedbymixing2ormoreingredientsoneofwhichmustbe
eitherstarch,talcorkaolin.
•Talc&kaolinaremorecommonlyusedbecausetheyarechemicallyinert.
•However,theseingredientsreadilygetscontaminatedwithpathogenicbacteria,thesemustbe
sterilizedbyDRYHEATMETHOD(160°Cfor2hours)beforeuse.
15Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

16. •DustingpowdersaredispensedinSIFTERTOPcontainersoraerosolcontainers.
•Pressureaerosolcontainersarecostlierthansiftertopcontainersbuttheyhelpineasyapplication
ofthepreparation.
•Dustingpowdercanalsobeappliedwiththehelpofpowderpufforsterilizedgauzepad.
•Dustingpowdersaregenerallyconsideredtobenon-toxicbuttheinhalationofitsfinepowdered
ingredientsbyinfantsmayleadtopulmonaryinflammation.
Dustingpowder
•R
x
Purifiedtalc(sterilised)50gm
Starch 25gm
ZnO 20gm
Salicylicacid 5gm
•Method:Powderalltheingredients.Mixtheminascendingorderoftheirweight.Passthemixed
powdermixturethroughsieveno.80.
•Aftersifting,mixthepowderslightly.Transferthemixtureinsiftertopcontainer.
16Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

17. B.SNUFFS
•Thesearefinelydividedpowderswhichareinhaledintonostrils.
•Theypossesantiseptic,bronchodilatorsanddecongestantaction.
•Theyaremainlyusedbythepatientssufferingfrombronchialasthma.
•Thesearedispensedinflatmetalboxeswithhingedlid.
C.DENTIFRICES/TOOTH POWDERS
•Theyconsistofveryfinelydividedsolidparticles,whichareappliedwiththehelpofatoothbrushfor
cleansingthesurfaceoftheteeth.
•Thecleaningactionmainlydependsontheabrasivesubstance.
•Abrasivesubstancessuchascalciumsulphate,sodiumchloride,sodiumcarbonate&magnesiumcarbonate
arecommonlyused.
•Useofastrongabrasivesubstanceisavoidedsinceitmaydamagetheenameloftheteeth.
•Asuitableflavouringagent,detergentorsoapmaybeincludedintheformulationofadentalpowder.
17Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

18. •Eg:Dispense50gofdentifrices
R
x
Hardsoap,infinepowder 50g
Precipitatedcalciumcarbonate935g
Saccharinsodium 2g
Peppermintoil 4ml
Cinnamonoil 2ml
Methylsalicylate 8ml
Makeatoothpowder.
Method:Trituratethesaccharinsodium,theoilandMethylsalicylatewithaboutonehalfofthe
precipitatedcalciumcarbonateandmixthesoapwiththeremainingportionofprecipitatedcalcium
carbonate.Mixtwopowdersthoroughlyandthenpassitthroughafinesieve.
18Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

19. D.INSUFFLATIONS
•Thesearemedicatedpowdersmeantforintroductionintobodycavitiessuchasnose,throat,ears&vaginawiththehelpof
apparatusknownas“insufflator”
•Itsprays/blowsthepowderasathinstreamoffinelydividedparticlesalloverthesiteofapplication
•Insufflationsareusedtoproducealocaleffectortoproduceasystemiceffectfromadrugthatisdestroyedingut.
•Nowadays,insufflationsareavailableaspressureaerosols.
•DISADVANTAGES OFINSUFFLATIONS:
•Doseaccuracyisaproblem.
•Insufflatorsgetblockedwhenwetpowdersareused
19Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

20. •3.SIMPLE&COMPOUND POWDERSFORINTERNALUSE
SIMPLEPOWDERS
•Thesearethepowderswhichconsistofasingleingredienteitherincrystallineoramorphousform.
•Whenthepowdersareincrystallineform,theyshouldbereducedtofineform.
•Theminimumquantityofeachpowdershouldnotbelessthan100mgsothatitcanbehandledconvenientlybypatients&
weighedaccurately.
•Theweightrequiredforeachdoseiscalculated&totalnumberofdosearewrappedinseparatepapers.(300mgofAspirin
6doses}
•Example:
Dispense6powdersofAspirin,eachpowdercontaining300mgofAspirin
R
x
Aspirin300mg
•Direction:1powdertobetakenafterevery8hours
•Method:Powdertheaspirin&weighrequiredquantity.
•Weigh300mgforeachpowder.Wrapeachdoseinindividualpowderpaper.Prepare6powders.Packitflaptoflap&
restrainedwithelasticband.
20Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

21. COMPOUND POWDERS
•Thesearethepowderswhichconsistof2ormoreingredientseitherincrystallineoramorphousform;which
aremixedtogether&thendispensedintonumberofdoses.
•Whenthepowdersareincrystallineform,theyshouldbereducedtofineform.
•Theminimumquantityofeachpowdershouldnotbelessthan100mgsothatitcanbehandledconveniently
bypatients&weighedaccurately.
•Theweightrequiredforeachdoseiscalculated&totalnumberofdosearewrappedinseparatepapers.
•Example:Dispense5dosesofAspirin,Paracetamol&Caffeinepowder.
R
x
Aspirin 300mg
Paracetamol150mg
Caffeine 50mg
Method:Powderedallingredients.Weighthecalculatedquantityofeachingredient.Mixtheminascending
orderoftheirweight.
Weigh500mgofmixedpowderforeachdose.Wrapeachdoseinindividualpaper&thenpacked.
21

22. 4. POWDERS ENCLOSED IN CACHETS
•Cachets are the solid unit dosage formsof medicament in which drug is enclosed in tasteless sheet made by
pouring mixture of rice flour and water between two hot, polished, revolving cylinders. Water is evaporated
and sheet of wafer formed, drug is enclosed in it.
TYPES:
1. DRY SEAL CACHETS
2. WET SEAL CACHETS
•Cachets are known as “WAFER CAPSULE”
•They are very hard to swallow as such; hence they are softened by dipping in water for few seconds & then
placed in tongue & swallowed with a large quantity of water.
•After swallowing, cachets get disintegrated & drug is released.
ADVANTAGES OF CACHETS:
•Easy preparation (minimal machinery use)
•Disintegrate quickly in stomach
•Large doses can be incorporated in cachets (even upto1.5gm) 22

23. DISADVANTAGES OFCACHETS:
•Mustbesoftenedbeforeswallowing
•Easilydamaged
•Can’tprotectthedrugfrommoisture&light
•Shellofcachetsarefragile
•Occupymorespace
5.TABLETTRITURATES(mouldedtablets)
•Thesearepowdersmouldedintotablets.
•Mouldedtabletsareflat,circulardisc&usuallycontainpotentsubstancewhichismixedwithlactose,
dextroseorothersuitablediluent.
•Theapparatususedforpreparationoftablettrituratesismadeupofstainlesssteelorplastic.
•Themouldsareavailableinseveralsizeshavingcapacityrangingfrom30mgto250mg.
•Generally50-250tablettrituratescanbepreparedatatimefromatablettrituratemould.
•Thesolidmedicament&diluentarefinelypowdered&convertedintostiffpastewiththehelpofalcohol
60%.
23Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

24. Tablet mould:
•it consists of an upper perforated plate which is having exactly the same number of holes as that of number of pegs in a
lower plate.
•The upper plate is placed on a clean tile & the paste is filled into holes completely with the help of spatula.
•Upper plate is then placed over the lower plate.
•A little pressure is applied over the top plate which will eject the mouldedtablets.
•Ejected tablets are spread over on a clean surface & dried by using hot air oven or by keeping them in a warm place.
DISPENSING OF POWDERS INVOLVING SPECIAL PROBLEMS
•VOLATILE SUBSTANCES
•HYGROSCOPIC SUBSTANCES
•DELIQUESCENT SUBSTANCES
•EUTECTIC MIXTURES
•INCORPORATION OF LIQUIDS
•EXPLOSIVE SUBSTANCES
•POTENT DRUGS
24Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

25. VOLATILESUBSTANCES
•Certainvegetablepowderscontainvolatileoils.
•Volatilizationofsubstanceslikementhol,camphormaytakesplaceonincorporationinpowders.
•Topreventlossofvolatileoils,thesedrugsfirsttrituratedlightlyinmortar.
•Volatilizationcanbeminimizedbytheuseofdoublewrapping.
•Theinnerwrappershouldbeofwaxpaper&outerwrappermaybeofanythickpaper.
HYGROSCOPIC SUBSTANCES
•Thesubstanceswhichabsorbmoisturefromtheatmospherearecalledashygroscopicsubstances.
•Suchsubstancesareusuallysuppliedingranularforminordertoexposelesssurfaceareatotheatmosphere.
•Thesepowdersshouldnotbefinelypowdered.
•Thesepowdersshouldbedoublewrapped.
DELIQUESCENT SUBSTANCES
•Certainsubstancesabsorbmoisturetosuchalargeextentthattheygointosolutionstate&arecalledasdeliquescent
substances.
•Examples:NH
4Cl,NaBr,NaI,ZnCl
2
•Suchsubstancesareusuallysuppliedingranularforminordertoexposelesssurfaceareatoatmosphere.
•Thesepowdersshouldnotbefinelypowdered.
•Thesepowdersshouldbedoublewrapped&furthercanbewrappedinaluminumfoilorplasticcover.
25

26. EUTECTICMIXTURES
•When2ormoresubstancesoflowmeltingpointaremixedtogethertheyliquefyduetotheformationofa
newcompoundwhichhasameltingpointlowerthantheroomtemperature.
•Suchsubstancesareknownaseutecticsubstances.
•Examples:Menthol,thymol,camphor,phenol,chloralhydrateetc.
•Thesesubstancescanbedispensedby2methods:
Dispenseasseparatesetofpowderswithdirectionsthatonesetofeachkindshallbetakenasadose.
Mixingwithanequalamountofinertabsorbent(talc,kaolin,lactose)
INCORPORATION OFLIQUIDS
•Ifthequantityofliquidtobeaddedissmall,itmaybetrituratedwithanequalquantityofpowder&thenrest
oftheliquidincorporatedinsmallamountswithcontinuoustrituration.
•Ifquantitiesofliquidarelargethenabsorbentmaterialmustbeadded.
EXPLOSIVESUBSTANCES
•Whenanoxidizingagent(potassiumchlorate)ismixedwithreducingsubstances(tannicacid);thereare
chancesofviolentexplosionwhichmayleadtoseriousconsequences.
•Asfaraspossible,suchprescriptionsshouldnotbedispensed.
26Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

27. •Ifunavoidable;thenpowdereachingredientseparately&dispensetheminseparatepaper&withsuitable
directiontothepatientregardingitsuse.
•Dispensethefollowingexplosivepowder.
R
x
Potassiumchlorate0.6gm
Tannicacid 0.3gm
Sucrose 0.3gm
POTENTDRUGS
•Thesubstanceshavingamaximumdoseoflessthan60mg&poisonoussubstancesareregardedaspotent
drugs.
•Smallquantitiesofpotentdrugsshouldnotbeweighedondispensingbalance.
•Usuallypotentdrugismixedwithasuitablediluent(lactose)byfollowinggeometricaldilutionmethod&
thendispensed.
•Thewholeofthediluentshouldneverbeaddedtothedrugatonetimeotherwisethepotentdrugwillnotbe
mixeduniformly.
R
x
Codeinephosphate10mg
Makeapowder&sendsuch5powders.
27Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

28. Direction:TakeIpowderbeforegoingtobed.
Method:Thequantityofcodeinephosphateprescribedisverysmall&notpossibletoweighondispensing
balance.
•Henceweigh100mg(minimumweighablequantity)&900mgoflactose.Mixthemingeometricdilution
method.
•Aftercompletemixing,weigh100mg(whichcontains10mgofcodeinephosphate)&packinpaper.
•Prepare5suchpowders,label&dispense.
28Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

29. GRANULES
•Thesearetheaggregatesoftheparticlesofdrug.Theyarepreparedbyusinganygranulatingagentlikestarchpaste.
•Granulesfacilitatetheincorporationofcolours&flavourstorendertheproductattractive&tasteful.
•Drugswhichareunstableinliquidformcanbedispensedasgranules;whicharetomixedwithwaterjustbeforeits
administration.
ADVANTAGES OFGRANULES
•Improvesstabilityagainsthumidity
•Improvespalatability
•Effervescentgranulesdonotshowviolenteffervescentreactionuponadditiontowatercomparedtoeffervescentpowders.
•Ensuresuniformdistributionofdrugs.
•Increasesbulkdensitythatinturnreducesthevolume&sizeofcontainerrequiredforpacking.
•Suitableforlargedoseofdrugs
DISADVANTAGES OFGRANULES
•Notsuitableforwatersensitivedrugs.
•Slowerdrugactioncomparedtopowders.
•Involvesmulti-stepprocesslikemoistening&drying.
•Requiresmoreskillwhilepreparinggranulesthaninmakingpowders.
29

30. EFFERVESCENT GRANULES
•Thesearespeciallypreparedsoliddosageformofmedicament,meantforinternaluse.
•Theyusuallycontainamedicamentmixedwithcitricacid,tartaricacid,sodiumbicarbonate.
•Saccharin/sucrosecanbeaddedassweeteningagent.
•Beforeadministration,thedesiredquantityisdissolvedinwater;theacid&bicarbonatereacts
togetherproducingeffervescence.
•ThereleaseofCO₂masksthebitter&salinetasteofdrug.
•CO₂helpsinabsorptionofdrugsinstomach.
METHODOFPREPARATIONOFEFFERVESCENT GRANULES
1.HEATMETHOD(Heatfusionmethod)
2.WETMETHOD
30Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

31. 1. HEAT METHOD
•A large stainless steel or porcelain evaporating dish is placed over boiling water bath.
•The dish must be sufficiently hot before transferring the powder into it.
•Citric acid liberates water of crystallization, which is utilized to make a coherent mass.
•If the powders are added first & then heated the dish will results in slow liberation of water of
crystallization & the water evaporates quickly.
•Hence powders are added to the hot dish to produce a coherent mass.
•The water needed for granulation is provided from two sources:
a) From water of crystallization of citric acid -The citric acid contains one molecule of water of crystallization which is
liberated during heating.
b)The water produced from the reactions of citric acid and tartaric acid with sodium bicarbonate.
3NaHCO
3 + C
6H
8O
7.H
2O C
6H
5Na
3O
7+ 3CO
2↑ + 3H
2O
Sodium Citric acid Sodium citrate
bicarbonate
2NaHCO
3+ C
4H
6O
6 C
4H
4Na
2O
6+ 2CO
2↑ + 2H
2O
Sodium Tartaric acid Sodium tartarate
Bicarbonate
31Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

32. •Generally,heatingstagetakes1to5minutes.
•Thedampmassisthenpassedthroughasievetopreparethegranulesofsuitablesize,driedinanovenata
temperaturenotexceeding60°Candthenpackedinanairtightcontainer.
•Lossofweightoccursduringgranulationasaresultof:
i.Evaporationfromthedampmixture.
ii.Lossofcarbondioxide.
•Theselossesconstituteapproximatelyone-seventhoftheweightofpowderusedandmustbetakeninto
considerationwhilecalculatingthequantityofgranulestobeprepared.
2.WETMETHOD
•Inthismethod,themixedingredientsaremoistenedwithanon-aqueousliquid(e.g.alcohol)topreparea
coherentmasswhichisthenpassedthroughanumber8sieveanddriedinanovenatatemperaturenot
exceeding60°C.
•Thedriedgranulesareagainpassedthroughthesievetobreakthelumpswhichmaybeformedduringdrying.
•Thedriedgranulesarepackedinairtightcontainers.
32Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

33. Eutectic Powder
•When2ormoresubstancesoflowmeltingpointaremixedtogethertheyliquefyduetotheformationofanew
compoundwhichhasameltingpointlowerthantheroomtemperature.
•Suchsubstancesareknownaseutecticsubstances.
•Examples:Menthol,Thymol,Camphor,Phenol,Chloralhydrateetc.
•Thesesubstancescanbedispensedby2methods:
•Dispenseasseparatesetofpowderswithdirectionsthatonesetofeachkindshallbetakenasadose.
•Mixingwithanequalamountofinertabsorbent(tale,kaolin,lactose)
•Formula: Ingredients Official formula
(1 dose)
Camphor 2 gm
Menthol 1 gm
Light kaolin 3 gm
33Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

34. Principle:
•Whensolidsoflowmeltingpointaremixedtogether,theresultantmixturehasameltingpointlowerthan
roomtemperature,producingaliquefiedmass.SuchacombinationisknownasaEutecticmixtureCamphor
andmentholtogetherformaEutecticmixture.
•Tosupplythesesubstancestogetherintheformofpowder,absorbentssuchasmagnesiumcarbonateorlight
magnesiumoxideorkaolincanbeusedineitheroneofthefollowingways
a)Dispenseasseparatesetofpowderswithdirectionsthatonesetofeachkindshallbetakenasadose.
b)Mixeachingredientseparatelywithanequalquantityoftheabsorbentandthenlightlymixthetwoportions.
c)Mixtheingredientsoftheeutecticmixturetoobtaintheliquidthentrituratethisliquidwithenoughabsorbent
powdertogiveafreeflowingpowder.
•Lightkaolinormagnesiumcarbonateactasdiluentorabsorbentandpreventcontactbetweenthe
medicamentsandabsorbsanyliquidthatmaybeproduced.
34Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

35. Procedure:
1.Camphorandmentholwerefinelypowdered.
2.Requiredquantitiesofcamphor,mentholandkaolinwereweighed.
3.2gmofkaolinwasmixedwith2gmofcamphorbylighttrituration.
4.1gmofkaolinwasmixedwith1gmofmentholbylighttrituration.
5.Twopowdersweremixedbyspatulationingeometricalratio.
6.Requiredquantityofpowderwasweighedandtransferredtoaclean,drywidemouthedcontainerwithascrewcap.
Category:Carminative.
Direction:Dispenseonepacketofpowderinaglassofwateranddrink
Storage:Storeinacoolanddryplace.
35Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

36. Effervescent Powder
•Effervescentpowdersarepresentedassingle-doseormultidosepreparationsandgenerallycontainacidsubstancesand
carbonatesorbicarbonateswhichreactrapidlyinthepresenceofwatertoreleasecarbondioxide.Theyareintendedtobe
dissolvedordispersedinwaterbeforeadministration.
Formula:
Ingredients Official formula
(1 dose)
Sodium Potassium Tartarate 7.5 gm
Sodium Bicarbonate 2.5 gm
Tartaric acid 2.5 gm
36Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

37. Principle:
•Sodiumbicarbonateandtartaricacidarehygroscopicsubstances.Inpresenceofmoisturesodiumbicarbonatereacts
withtartaricacidandevolvescarbondioxide.Thereforetheyhavetobeenclosedinseparateenclosureslinedwith
butterpaper(doublewrapper).
•Wheneffervescentpowderisaddedtothewaterjustbeforeadministration,sodiumbicarbonatereactswithtartaric
acidinwaterandproduceseffervescence(byevolvingcarbondioxide).Itincreasesthetasteofthemixture.
•Sodiumpotassiumtartarateisusedassalinepurgative.
Procedure:
1.Slightlyexcessthantherequiredquantitiesofsodiumpotassiumtartarateandsodiumbicarbonatewereweighedand
trituratedeachintoafinepowder,separately.
2.Requiredquantitiesoffinepowderofsodiumpotassiumtartarateandsodiumbicarbonatewereweighedandmixed
bytriturationingeometricalratio.
3.Itwasthenenclosedinabluewrapperlinedfrominsidewithbutterpaper.
4.Requiredquantityoffinelypowderedtartaricacidwasweighedandenclosedinawhitewrapperlinedwithbutter
paper.
5.Twopowdersweretiedwithpaperribbonandweredispensedinaneatlylabeledenvelop. 37

38. Category:Salinepurgative.
Direction: Dissolve one blue colourpacked paper content in a half tumbler of water, and add one white colour
packed paper content and take as directed by the physician, while effervescing.
Storage: Store in a dry place.
38
Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP,
Mangalore

39. IMPORTANT QUESTIONS
SHORTESSAYS(5MARKS)
1.Definepowders.Classifypowders.
2.ExplainGeometricdilutionwithanexample.
3.Discussthedifferentmethodsofmixingpowders.
4.Explainsimpleandcompoundpowderswithanexample.
5.Howdoyouprepareeffervescentgranulesbythefusionmethod?
6.Howdoyoudispenseeutecticpowders?
7.Explaininsufflationswithexamples.
8.Writetheadvantagesanddisadvantagesofpowdersasthedosageform.
9.Defineandclassifypowdersbasedonofficialgradesofpowders.
10.Explaindustingpowderswithexamples.
11.Explainthepreparationofeutecticpowders.
12.Howdoyouprepareeffervescentgranulesbyheatmethod?
13.Howdoyoudispenseeutecticpowders,explosivepowdersandpotentdrugsasapowderdosageform?
14.Explaininsufflations,snuffsanddentifriceswithsuitableexamples.
39Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

40. 15.Explaindustingpowdersanddentifriceswithexamples
16.Discussbrieflyaboutbulkpowdersforexternaluse.
17.Define&classifydustingpowders.Writeanoteonpreparationofdustingpowder.
18.Writetheprinciple&procedureinvolvedinthepreparationofeffervescentpowders.
19.Howdoyoudispensehygroscopicsubstances,deliquescentsubstancesandvolatilesubstancesasapowderdosage
form?
20.Definegranules.Classifythem.Giveadvantages&disadvantagesofgranules.
SHORTANSWERS(2Marks)
1.Definehygroscopicanddeliquescentpowders.
2.Howdoyoudispensepotentpowders?
3.Whyisadoublewrappingofpowderrequired?
4.Classifypowders.
5.Definecachetsforexample.
6.Definepowderwithanexample.
7.Defineandclassifydustingpowders.
8.Defineeutecticpowders.
40Prepared By: Sumana , Dept. of. Pharmaceutics, SDCP, Mangalore

41. 9.Defineinsufflationswithexamples.
10.Definesimpleandcompoundpowders.
11.Whataretheingredientsofdustingpowders?
12.Definegeometricdilution.
13.Enlistthemethodsofmixingpowders.
14.Definepharmaceuticalpowders.Giveexamples.
15.Giveatleasttwoadvantages&disadvantagesof
16.Definehygroscopicanddeliquescentpowders.
17.Howdoyoudispensepotentpowders?
18.Whyisdoublewrappingofpowderrequired?
19.Whataresnuffs?
20.Howdoyoudispenseapowdercontainingvolatilesubstances?
21.Howdoyoudispenseapowdercontaininghygroscopicsubstance?
22.Howdoyoudispenseapowdercontainingdeliquescentsubstance?
23.Howdoyoudispenseapowdercontainingexplosivesubstances?
24.Howdoyoudispenseapowdercontainingeutecticsubstances?
25.Howdoyouovercomeaproblemduringincorporationofaliquidintoapowder?
26.Defineeffervescentgranules.
27.Nameanyfourtypesofpowderdosageforms.
41