Monophasic & Biphasic Liquid Dosage Form.pdf

Definitions and preparations of MonoPhasic & Biphasic Liquid Dosage Form

1. Prepared by: Dr.Harshil M Patel, Assistant Professor
Dept. of Pharmaceutics, SNLPCP, UMRAKH.

3. 3
MONOPHASIC LIQUIDS
➢Thecompoundingofsolutionretainsanimportantplaceintherapeutics
owingtothesimplicityofpreparationandrapidabsorptionofsoluble
medicinalproducts.Solutionsareofparticularvalueforpaediatric,geriatrics
andpsychiatricpatientswhohavedifficultyinswallowingsoliddosageforms
andincaseswhereindividualizeddosagesarerequired.
➢Dosageformsmeanteitherforinternal,externalorparenteralusemaybe
sub-classifiedintomonophasicorbiphasicliquiddosageforms.The
monophasicliquiddosageformsconsistofeithertrueorcolloidalsolutionsor
solubilizedsystem.Alltheseconsistofonlyasinglephaseandmayhave
eitheraqueousornon-aqueoussolventsasthebase.

4. 4
Gargles
➢Garglesareaqueoussolutionusedtopreventortreatinfection.Theyareusuallyavailablein
concentratedformwithdirectionfordilutionwithwarmwaterforuse.
➢Theyarebroughtintointimatecontactwithmucousmembraneofthroatandallowedtoremainin
contactwithitforfewseconds,beforetheyarethrownoutofmouth.Theyareusedtorelievesoreness
inmildthroatinfection.
➢Phenolorthymolisusedasantibacterialagentingargles.Phenolorthymolmaybepresentinlow
concentrationswhichexertmildanestheticeffect;KCIisincludedingarglepreparationforitsweak
astringenteffect,andstimulationtheflowofsaliva,whichreleaseddrugs.Garglediffersfrommouth
washesinthattheyarelightmedicatedoralmixturebedilutedwithwaterbeforeuse.
➢Forexample:Phenolgargle,KCIO3gargles.
Storage:Garglesshouldbedispensedinclear,flutedglassbottles.Colouredbottlesarerequiredtobe
usedifgarglesneedprotectionfromsunlight.
Labeling:ForEXTERNALUSEONLY.NOTTOBESWALLOWED.

5. 5
Gargles
Formula:Phenolgargle
Rx
Phenolglycerin-5ml
Amaranthsolution-1ml
Purifiedwater-q.s.to100ml
Thisgarglemaybepreparedbymixingamaranthsolution(1%w/vinchloroformwater)withasmallquantityofwater
andaddingPhenolglycerin(16%w/wphenoland84%w/wglycerin)toit.Thesolutionisstirredandmadeupto
volumewithpurifiedwater.Thegargleismeanttobedilutedwithequalquantityofwarmwaterbeforeuse.
Uses:Antibacterialeffect,astringenteffect,mildanestheticeffect.
Packaging:Packinflipflopbottles,waterproofpacking.

6. 6
Mouth Wash
➢Theseareaqueoussolutionswithapleasanttastetoclean,deodorizethebuccalcavity.Mouthwashes
haverefreshing,antisepticandantibacterialactivityandpreventHalitosis.Theymayalsocontain
alcohol,glycerin,syntheticsweeteners,surfactants,Flavouringandcolouringagents.Theymaybe
eitheracidicorbasicintheirreactionandinsomeinstancesarefairlyeffectiveinreducingbacterial
concentrationandodorsinthemouthforshortperiodsoftime.
Forexample:Compoundsodiumchloridemouthwash,Zincchloridemouthwash,Fluoridemouthwash.
Storage:Keepincoolanddryplace,Dispenseinclear,flutedbottles.
Labeling:
➢FOREXTERNALUSEONLY
➢Nottobeswallowedinlargeamount
➢Packinnarrowmouthbottle

7. 7
Mouth Wash
Formula:
Rx
ZincsulphateandzincchloridemouthwashB.P.C.
Zincsulphate-20g
Zincchloride-10g
Oilutehydrochlorideacid-10ml
Compoundtartarzinesolution-10ml
Chloroformwatertoproduce-1000ml
➢ThepreparationmaybemadebydissolvingZincsulphateandZincchlorideinsmallquantityofChloroform
solution.Tothisisaddeddilutehydrochloricacidandcompoundtartrazinesolutionandthefinalvolumeismadeup
withwater.
➢ZincsulphateandZincchlorideincludedinthepreparationactsasastringents.Chloroformwateractsasthe
flavouringagentandpreservativewhiletartrazineservesasthecolour.Zincsulphateusuallycontainsasmall
quantityofoxychloridewhichmaymakethesolutionturbid.Thishoweverdisappearsonadditionofdilute
hydrochloricacid.

8. 8
Throat Paint
➢Solutionordispersionofoneormoreactiveagents.Throatpaintsareviscousliquidpreparationsusedformouthandthroatinfections.
Glyceriniscommonlyusedasabasebecausebeingviscousitadherestomucousmembraneforalongperiod.Glycerinprolongsthe
actionofmedicaments.Glycerinalsoprovidessweettastetopreparation.
Forexample:Boroglycerin,Phenolglycerinthroatpaint.
Storage:Throatpaintshouldbestoredinairtightcontainerandincoolplace.
Labeling:ForEXTERNALUSEONLY.Nottobeswallowed.
Formula:
RX
Potassium iodide -2.5 gm
lodine-1.25 gm
Alcohol -4 ml
Water -2.5 ml
Peppermint oil -0.4 ml
Glycerin -100 ml
➢Dissolve the potassium iodide in water. Add the iodine and stir until completely dissolved. Dissolve peppermint oil in alcohol 90% in a
small container and transfer it into iodine solution.
➢Transfer paint into a measuring cylinder and make up the volume to q.s.
➢Paint are applied with soft brush.
Packing: A wide mouth, fluted, light resistant, screw car glass bottle is used and dispensed in amber coloured bottle.

9. 9
Ear Drops
➢Eardropsareliquidpreparationsmeantforinstillationintotheear.Inthesepreparations,thedrugisusually
dissolvedorsuspendedinasuitablesolventsuchaspropyleneglycol,polyethyleneglycol,glycerolalcoholand
wateroramixtureofthese.Aqueousvehicleisgenerallynotpreferredbecausethesecretionsintheeararefattyin
natureandassuchthesedonoteasilymixwithwater.
➢Eardropsaregenerallyusedfortheircleansing,painrelievingandantisepticactions.Themainclassesofdrugs
includeanalgesicslikebenzone,antibioticslikeneomycinandchloramphenicolandanti-inflammatoryagentssuch
ascortisoneanddexamethasone.Waxsofteningagentsincludehydrogenperoxideandsodiumbicarbonate.Ear
dropsareusuallysuppliedinambercoloured,glassbottleswithateatanddropperclosureorplasticsqueeze
bottles.
➢Example:ChloramphenicolEarDrops
Chloramphenicol–5g
Propyleneglycolq.sto100ml
➢ChloramphenicoleardropsmaybepreparedbydissolvingChloramphenicolinsufficientquantityofPropylene
glycolandfinallymakingupthefinalvolumewithit.

10. 10
Nasal Drops
➢Nasaldropsareliquidpreparationsintendedforinstillationintothenostrilsusuallywiththehelpofadropper.Nasal
dropsaremostlybasedonaqueousvehiclesalthoughoilydrops(containingliquidparaffinofsuitableviscosity)are
notuncommon.Oilyvehiclesaregenerallynotpreferredsincetheoilmayretardtheciliaryactionofthemucosa
andmayevencauselipoidpneumoniaifdropsoftheoilenterthelungs.Nasaldropsaregenerallyformulatedto
resemblethenasalsecretionsascloselyaspossible.Thus,theseareusuallyisotonicandslightlybufferedto
maintainapHof5.5to7.5.Additionally,thepreparationismadeslightlyviscouswiththehelpofthickeningagents
likemethylcellulosetomatchitsviscositywiththatofthenasalsecretions.
➢Example:EphedrineNasalDrops
EphedrineHydrochloride-0.5g
Chlorbutol
SodiumChloride
Purifiedwaterq.sto100ml
➢ThedropsmaybepreparedbyfirstdissolvingChlorobutolinsmallquantityofhotwaterfollowedbycoolingthe
solutiontoroomtemperature.Otheringredientsarethendissolvedinthesolution,whichisfilteredandthefinal
volumeismadeupwithwater.ThesedropsareusedasdecongestantwithEphedrineactingastheactive
medicament.ChlorobutolactsasthepreservativewhileSodiumchlorideisaddedtomakethesolutioniso-osmotic
withnasalsecretions.

11. 11
Nasal Sprays
➢Nasalspraysaresuspensionsorsolutionofdrugsintendedforsprayingintothenostrils.
Thechiefusesofnasalspraysaretorelievenasalcongestionandinflammationandtotreat
infections.Theyareintendedtoberetainedinthenasaltract,theyareusuallyviscousand
coarsesincefinedropletstendtopenetratefurtherintotherespiratorytract.These
preparationsareusuallysuppliedinpressurizedcontainersorplasticsqueezebottles.

12. 12
Enemas
➢Enemasareliquidpreparationsmeanttobeintroducedintotherectumforcleansing,therapeuticordiagnostic
purposes.Evacuationenemasarerectalinjectionsemployedtoevacuatethebowelinconstipationorbeforean
operation.e.g.,Enemaofsoap,Sodiumphosphateenema,Oliveandarachisoilenema,etc.Retentionenemasare
usuallyemployedtoinfluencethegeneralsystembyabsorptionortoaffectlocallytheseatofdisease.Theymay
possessanthelmintic(quassia),nutritive,sedative(chloralhydrate),oranti-inflammatory(corticosteroids)
properties,ortheymaycontainradio-opaquesubstances(bariumsulphate)forX-rayexamination.
➢Largevolumeenemasareadministeredfromadouchecanandshouldbewarmedtobodytemperaturebeforeuse.
Smallvolumeenemasareavailableinpolytheneorpolyvinylchloridebagssealedtoarectalnozzleandtheseare
moreconvenientforpersonaladministrationsincethepatienthassimplytoinsertthenozzleandsqueezethebag.

13. 13
Enemas
➢Enemasareliquidpreparationsmeanttobeintroducedintotherectumforcleansing,therapeuticordiagnostic
purposes.Evacuationenemasarerectalinjectionsemployedtoevacuatethebowelinconstipationorbeforean
operation.e.g.,Enemaofsoap,Sodiumphosphateenema,Oliveandarachisoilenema,etc.Retentionenemasare
usuallyemployedtoinfluencethegeneralsystembyabsorptionortoaffectlocallytheseatofdisease.Theymay
possessanthelmintic(quassia),nutritive,sedative(chloralhydrate),oranti-inflammatory(corticosteroids)
properties,ortheymaycontainradio-opaquesubstances(bariumsulphate)forX-rayexamination.
➢Largevolumeenemasareadministeredfromadouchecanandshouldbewarmedtobodytemperaturebeforeuse.
Smallvolumeenemasareavailableinpolytheneorpolyvinylchloridebagssealedtoarectalnozzleandtheseare
moreconvenientforpersonaladministrationsincethepatienthassimplytoinsertthenozzleandsqueezethebag.

14. 14
Syrups
➢Syrupsaresweetviscousconcentratedaqueoussolutionofsucroseinpurifiedwater.
SimplesyrupI.Pcontains66.7%w/wsucroseinpurifiedwater(100ml)
SimplesyrupUSPcontains85%w/vsucroseinpurifiedwater(100m.)
MedicatedSyrup:Containsatherapeuticormedicinalagente.g.Coughsyrup.
FlavouredSyrup:ContainsFlavouringagentbutnomedicinalsubstancese.g.Cherrysyrup.

15. 15
Advantages of Syrup
➢Syrupretardsoxidationbecauseitispartlyhydrolyzedintoitsreducingsugarsuchaslaevuloseand
dextrose.
➢Itpreventsdecompositionofvegetablesubstances.Syruphashighconcentrationofsugarhavinghigh
osmoticpressurewhichpreventsthegrowthofbacteria,fungi,microbes.Itactsasaselfpreservative.
➢Theyarepalatableduetothesweetnessofsugar.Itisavaluablevehiclefortheadministrationof
nauseousandbittersubstances.
➢Syrupsaregooddemulcentsandsoothingagentsandhencetheyareofspecialvalueincoughsyrup.
➢Syrupshavegoodpatientcompliance.

16. 16
Method of Preparation
➢HotProcess
➢Percolation
➢AgitationWithoutHeat
➢AdditionofMedicatingorFlavouringLiquidtoSyrup

17. 17
Hot Process
➢Thismethodisusedwhenactiveconstituentsisneithervolatilenorheatlabile.
Procedure
✓Weighedsucroseistakeninbeaker.
✓Purifiedwaterisadded.
✓Heatedonwaterbath(lessthan70°C)tillasolutionisobtained.
✓Productisfiltered.
✓Volumeismadeuptoq.s.
✓Excessiveheatmayleadstoinversionofsucrose.

18. 18
Percolation
➢Sucroseisplacedinpercolator.
➢Waterispassedthroughsucroseslowly.
➢Neckofpercolatorispackedwithcotton.
➢Rateofpercolationregulatesrateofdissolution.
➢Aftercompletedissolutionfinalvolumeismadeuptoq.s.

19. 19
Agitation Without Heat
➢Sucroseandotheringredientsareweighedproperly.
➢Dissolvedinpurifiedwater.
➢Keptinabottleofabouttwicethevolumeofsyrupfollowedbycontinuousagitation.
➢Preparedsyrupvolumeismadeuptoq.s.

20. 20
Addition of Medicating or Flavouring Liquid to Syrup
Thismethodisusedwhenfluidextracts,tincturesortheotherliquidsaretobeaddedtosyrup.
➢Alcoholisaddedtodissolvetheresinousoroilysubstances.
➢Alcoholactsasapreservativealso.

21. 21
Formulation of Syrup
Vehicle:Syrupsarepreparedbyusingpurifiedwater.
Adjuncts:Thefollowingadjunctsaregenerallyaddedtoimprovetheformulationofsyrup.
ChemicalStabilizer:Glycerin,sorbitol,propyleneglycolisaddedinsmallquantitytosyruptopreventthecrystallization.
Colouringagent:Manysyrupareattractivelycolouredwithcoaltardyessuchasamaranth,compoundtartarazineand
GreenS.
Flavouringagents
Tinctures:Lemonandgingertincture
Fruitjuice:Cherry,Raspberry
Essence:Vanilla,orange
Preservatives:Syrupsareselfpreservative.Generally,Benzoicacid,Sodiumbenzoate,Methylparabenetc.
Storage:Storedinwelldried,completelyfilledandwellstopperedbottleinacooldarkplace.Storeatatemperaturenot
exceeding25°C.

22. 22
Elixir
Elixirsaredefinedasclear,aromatic,sweetened,hydroalcoholicliquidsintendedfororalus
➢Theyprovideapalatablemeansofadministeringpotentornauseousdrugs.Elixirsarelesssweetandlessviscousthen
syrupmaycontainlessornosucroseElixirsaremorestablethansyrupsandhencepreferredoversyrupElixirscontain
4-40%ofalcohol(ethanol).
➢Theymaycontainglycerinandsyrupforincreasingthesolubilityofmedicamentsorforsweeteningpurpose.Elixirsmay
alsocontainsuitableFlavouringandcolouringagentsPreservativesarenotneededinelixirsasalcoholcontentis
sufficienttoactaspreservative.
TypesofElixir:
➢Non-medicated:Notcontainmedicamentandusedasflavoringagent.Forexample:Aromaticelixir.
➢Medicated:Whichcontainapotentdrugsuchasantibiotics,antihistamines,sedatives.

23. 23
Method of Preparation
➢ElixirsarepreparedbysimpledissolutionwithagitationorbymixingtwoormoreliquidsIngredientsaredissolvedintheir
respectivesolvents.Forexamplealcoholsolubleingredientsinalcoholandwatersolubleinwater.
➢Alcoholicstrengthismaintainedbyaddingtheaqueoussolutiontothealcoholicsolution.
➢Themixtureisthenmadeuptothedesiredvolume(q.s.).
➢AtthisstagetheproductmaynotbeclearduetoseparationofsomeoftheFlavouringagentbecausethealcoholic
strengthisreduced.
➢Thenelixirallowedtostandforsometimeheretheoilglobulesstartsprecipitating.
➢Thenelixirisfiltered.
➢Talccanbeaddedtoabsorbtheexcessofoils.
➢Filtrationgivesclearproduct.

24. 24
Formulation of Elixir
1.Vehicles:Theelixirsareusuallypreparedbyusingwater,alcohol,glycerin,sorbitol,andpropyleneglycol.Certainoilsare
easilysolubleinalcoholwherealcoholisusedascosolvent.30-40%ofalcoholmaybeusedtomakeaclearsolution.
2.Adjuncts
(a)Chemicalstabilizer:Thevariouschemicalsorspecialsolventsareusedinmanyelixirstomakesuitableelixir.E.g.For
neomycinelixir-citricacidisaddedtoadjustpH.
(b)Colouringagent:Amaranth,compoundtartrazinedyesareusedforcolouringpurpose.
(c)Flavouringagent:Blackcurrentsyrup,raspberrysyrup,lemonsyrupetc.
(d)Preservatives:Alcohol20%ormorepropyleneglycolorglycerolasavehicleisusedaspreservative.Chloroform
desirablestrength,benzoicacidmayalsobeused.
Container:Elixirsaredispenseinwellfilled,wellclosedairtightorglassbottleshavingscrewcaps.
Storage:Storeincoolanddryplace,protectedfromsunlight.

25. 25
Liniments
Liquidorsemi-liquidpreparationmeantforapplicationtotheskin.Thelinimentsareusuallyappliedtotheskinwithfriction
andrubbingofskin(ontheaffectedarea).Thelinimentmaybealcoholicoroilysolutionoremulsion.
Inalcoholicpreparation,alcoholhelpsinthepenetrationofmedicamenttotheskinandalsoincreasesitscounterirritant
effectandrubefacientaction.
Inoilyliniments,arachisoiliscommonlyusedwhichspreadsmoreeasilyontheskin.Somelubricantsmaycontainsoap
whichhelpsineasyapplicationoflinimentonskin.
Linimentshouldnotbeappliedonbrokenskinbecauseitmaycauseexcessiveirritation.Linimentcontainmedicament
possessinganalgesicaction,rubefacient,counterirritantpropertiesandappliedinjointpain,musclepainetc.
Shouldbedispensedincoloredflutedbottle.
Labelling:FOREXTERNALUSEONLY
Storage:Storedintightlyclosedcontainer.

26. 26
Lotions
➢Lotionsareliquidpreparationsmeantforexternalusewithoutfriction.
➢Theyareapplieddirecttotheskinwiththehelpofsomeabsorbentmaterial,suchascottonwool,gauzesoakedinit.
Lotionsarenotappliedtobrokenskinitmaycauseexcessiveirritation.Theinsolublemattershouldbedividedveryfinely
forpreparinglotions.Bentoniteasasuspendingagentisaddedtoit.
➢Lotionsareappliedforantisepticaction,astringentaction,germicidalactione.g.Calaminelotion.
➢Alcoholissometimesincludedinaqueouslotionsforitscoolingandsoothingeffecte.g.salicylicacidlotion.
Preparation:Lotionsarepreparedbytrituratingtheingredientstoasmoothpasteandthenaddingtheremainingliquid
phasewithtrituration.
Storage:Lotionsshouldbestoredinwellclosedandinairtightcontainer.
Labeling:FOREXTERNALUSEONLY

28. 28
Emulsion
➢Anemulsionisabiphasicliquidpreparationcontainingtwoimmiscibleliquids,oneofwhichisdispersedas
globulesintotheother.
➢Theliquidwhichisconvertedintoglobulesiscalledthedispersedphaseandtheliquidinwhichtheglobules
aredispersediscalledthecontinuousphase.
➢Normally,twoimmiscibleliquidscannotbedispersedforalongperiod.So,anemulsifyingagentisaddedto
thesystem.

29. 29
Advantages
➢Medicineshavinganunpleasanttasteandodourcanbemademorepalatablefororaladministrationinthe
formofanemulsion.e.g.castoroil,cod-liveroiletc.
➢Emulsionprovidesprotectionagainstdrugswhicharepronetooxidationorhydrolysis.
➢Variousexternalpreparationssuchas,cream,lotionandfoamaerosolsareformulatedinemulsion.
➢Thesterilestableintravenousemulsionscontainingfats,carbohydratesandvitaminscanbeadministered
tothepatientswhoareunabletotakethemorally.

30. 30
Types of Emulsions
➢Primaryemulsioncontainingoneinternalphase,forexample,
1.oil-in-wateremulsion(o/w)
2.water-in-oilemulsion(w/o).
➢Secondaryemulsionalsocalledmultiple-emulsioncontainstwointernalphases,forinstance,
1.o/w/o
2.w/o/w.
➢Itcanbeusedtodelayreleaseortoincreasethestabilityoftheactivecompounds

31. 31
Identification test for Emulsion
1.Dilutiontest:
➢Theemulsionisdilutedwithwater.Incasetheemulsionremainsstableafteritsdilution,itiso/wemulsion.
Thew/oemulsionbreaksonitsdilutionwithwaterbutremainstablewhendilutedwithoils.
2.Dyetest:
➢Thescarletreddyeismixedwiththeemulsion.Placeadropoftheemulsiononamicroscopicslide,coverit
withacover-slip,andexamineitunderamicroscope.
➢Ifthedisperseglobulesappearredandthe‘ground’colorless,theemulsioniso/wtype.
➢Thereverseconditionoccursinw/otypeemulsioni.e.,thedisperseglobulesappearcolorlessinthered
‘ground’.

32. 32
Identification test for Emulsion
3.Conductivitytest:
➢Waterisagoodconductorofelectricity,whereasoilisnon-conductorofelectricity.
➢Theconductivitytestcanbeperformedbydippingapairofelectrodesconnectedthroughalowvoltagebulb
intheemulsion.
➢Ifthebulbglowsonpassingtheelectriccurrent,theemulsioniso/wtype,becausewaterisincontinuous
phase.
➢Incasethebulbdosenotglow,theemulsionisw/otype,becauseoilisincontinuephase.

33. 33
Identification test for Emulsion
3.Fluorescencetest:
➢Certainfixedoilspossessthephysicalpropertyoffluorescinginthepresenceofultravioletradiation.
➢Onmicroscopicobservationofemulsionunderultravioletradiation,thewholefieldfluorescenceindicates
thatoilispresentincontinuousphase(w/otypeemulsion)anddropletsfluorescenceindicatesthatoilis
presentindispensedphase(o/wtypeemulsion).

34. 34
Classification of Emulsion
1.Classificationofemulsiononthebasisoftypeofemulsifyingagent:
A.NaturalGume.g.Acacia,Tragacanth
B.GumSubstitutee.g.Cellulose&itsderivatives
C.VariousSoap
D.Saponins
E.Starch
F.NaturalWaxe.g.Woolfat&beeswax
G.SyntheticWaxe.g.emulsifyingWax

35. 35
1.Classificationofemulsiononthebasisofmodeofadministration:
A.ForOralAdministration
Theseareusuallyo/wtypeofemulsionandareusedtoadministeoilshavingmedicinalvalue.E.g.
Castoroil,oliveoil,almondoil,cod-liver&liquidParaffin.
B.ForExternaluse
Thesemaybeeithero/wtypeorw/otype.Howevero/wemulsionarepreferredoverw/otype
emulsions.
C.ForParenteraluse
TheseareusedtoadministerfatsolublevitaminssuchasA,D,E&oilsolublehormonesbecause
theirabsorptioninthisformisveryrapid.

36. 36
Formulation of Emulsion
1.EmulsifyingAgents
2.Preservatives
3.Antioxidants
4.Flavours

37. 37
Emulsifying Agents
➢The emulsifying agents reduce the interfacial tension between two phase, oily phase & aqueous
phase and thus make them miscible with each other and form a stable emulsion.
➢Emulsifying agents are also known as emulgents or emulsifiers.
❖An ideal emulsifying agents should have the following Properties:
➢It should be capable of reducing the interfacial tension between the two immiscible liquids.
➢It should be compatible with other ingredients of the preparation
➢It should be non-toxic.
➢It should be capable to produce ad maintain the required consistency of the emulsion.
➢It should be chemically stable.

38. 38
Classification of Emulsifying Agents
1.Natural Emulsifying agents from vegetable Source
2.Natural Emulsifying agents from animal source
3.Semi Synthetic Polysaccharides
4.Synthetic emulsifying Agents
5.Inorganic emulsifying agents
6.Alcohols

39. 39
Natural Emulsifying agents from vegetable Source
➢These are carbohydrates which includes gums and mucilaginous substances. They are anionic in nature and produce
o/w type emulsions.
➢The emulsions prepared from these emulsifying agents need suitable preservative to preserve them because the
carbohydrates act as a medium for bacterial growth.
1.Acacia:
✓Acacia is considered to be the best emulsifying agents for the extemporaneous preparation of emulsion for internal use.
✓Emulsion prepared with gum acacia are attractive in appearance, quite palatable and relatively stable over a wide range
of pH (2 to 10).
2. Tragacanth:
✓Tragacanthaloneisrarelyusedasemulsifyingagentbecauseitproducesverycoarseandthickemulsion.The
appearanceandstabilityoftheemulsioncanbeimprovedbypassingtheemulsionthroughahomogenizer.
✓Astableemulsioncanalsobeproducediftragacanthisusedalongwithgumacaciaasemulsifyingagent.

40. 40
3. Agar:
✓It is not good emulsifying agent, as forms a very coarse and viscous emulsion. It is used as emulsifying
agents by preparing 2% mucilage, by dissolving in boiling water and cooled at 45 C.
4. Pectin:
✓It is used as emulsifying agents by preparing 1 % mucilage in water. It is incompatible with alkalies, strong
alcohol, tannic acid and salicylic acid.
5. Starch:
✓Starch mucilage is rarely used because it forms very coarse emulsions. It is generally used to prepare
enemas.

41. 41
Natural Emulsifying agents from animal source
1.Woolfat:
✓Itisgenerallyusedinemulsionwhicharemeantforexternaluse.Itproduceo/wemulsionandcanabsorb
about50%ofwater.
2.Eggyolk
✓Itismainlyusedinextemporaneouspreparationsmeantforinternalusebecauseitgelspoiledduring
transportation.Theemulsionpreparedwitheggyolkrequireproperpreservationandstorageina
refrigerator.
✓Itisusedasemulsifyingagentsintheconcentrationof12-15%.
3.Gelatin:
✓Itisusedintheconcentrationof1%asemulsifyingagents.Itismainlyusedfortheemulsificationofliquid
paraffin.
✓Theemulsionpreparedwithgelatinisquitewhiteandhaveanagreeabletaste.Butitneedsproper
preservationbecauseemulsionsarepronetobacterialgrowth.

42. 42
Semi-synthetic Polysaccharides
1.Methylcellulose:
✓ItIsasyntheticderivativeofcellulose.Itiswidelyusedassuspending,thickeningandemulsifyingagentsin
theconcentrationof2%.Itiscommonlyusedforemulsificationofmineralandvegetableoilsbutget
precipitatedinthepresenceoflargeamountofelectrolytes.
2.Sodiumcarboxymethylcellulose:
✓Itisusedasanemulsionstabilizerintheconcentrationof0.5to1.0%.Itissolubleinbothcoldandhot
water.

43. 43
Synthetic Emulsifying agent
1.Anionic:
✓Variousalkalisoaps,metallicsoaps,sulphatedalcoholsandsulphonatesareusedasanionicemulsifying
agents.
✓Soapemulsionsareusedforexternalapplication.SLSiscommonlyusedasemulsifyingagentsamongthe
sulphatedalcohols.ItProduceso/wemulsion.
2.Cationic:
✓Thequaternaryammoniumcompounds,suchasbenzalkoniumchloride,benzethoniumchloride,cetrimide
areusedascationicemulsifyingagents.Cationicsurfaceactiveagentsbearpositivechargeonthem.
✓Theymainlyusedinthepreparationsmeantforexternalusesuchasskinlotionandcream.
3.Non-Ionic:
✓Theglycerylesters,suchasGlycerylmonostearate,sorbitanfattyacidesterssuchassorbitan
monopalminatearecommonlyusednon-ionicsurfaceactiveagents.
✓Theyarewidelyusedinthepreparationofpharmaceuticalemulsions,becauseemulsionspreparedwith
non-ionicsurfactantsremainstableoverawiderangeofpHchanges.

44. 44
Inorganic Emulsifying Agents
✓Severalinorganicsubstancessuchasmilkofmagnesium(10-20%),MagnesiumOxide(5-10%),and
magnesiumaluminiumsilicate(1%)areusedtopreparedcoarseo/wemulsion.
✓Bentonite(5%)isusedtoprepareo/worw/oemulsions.Whenbentoniteisusedtoprepareo/wemulsion,
oilisaddedtothesuspensionofbentonite,whereaswhenitisusedtopreparedw/oemulsion,oilphaseis
placedinthecontainerandthenbentonitesuspensionisaddedtotheoilwithrapidstirring.

45. 45
Alcohols
1.Carbowaxes:
✓TheseareMainlyusedinthepreparationofointmentsandcreams.Carbowaxeshavingmolecularweight
between200-700areviscous,lightcolored,hygroscopicliquids.
✓Whereascarbowaxeswithmolecularweight1000andabovearewaxlikesolids.
2.Cholesterol:
✓Inthiscategory,cetylalcohol,stearylalcohol,cholesterolandglycerylmonostearateareusedtostabilize
theemulsion.
3.Lecithins:
✓Lecithinswhichformsw/oemulsion,israrelyusedasanemulsifyingagentsbecauseitdarkensincolour
whenexposedtolightandgetseasilyoxidised.

46. 46
Preservation of Emulsions
✓Emulsionswhicharepreparedbyusingemulsifyingagents,suchascarbohydrates,protiens,steroland
non-ionicsurfactantsmayleadtothegrowthofbacteria,fungiandmouldsinthepresenceofwater.
✓Thecontaminationofemulsionsbythesemicro-organismsmaycauseunplkeasantodour,tasteand
discoloration.
➢Thecontaminationofanemulsionmayoccurduetoanyoneofthefollowingreason:
✓Theequipmentusedinthepreparationofemulsionarecarelesslycleaned.
✓Byusingcontaminatednaturalemulsifyingagentssuchasgums,starchesandclays.
✓Theratioofoilandwaterisnotproper.
✓Byusingnotproperlystoreddeionizedandpurifiedwater.
✓pHofthepreparation.

47. 47
Antioxidants
✓Duringstorageofemulsion,thefatsandemulsifyingagentsundergooxidationbyatmosphericoxygen.
✓Thiscanbeavoidedbyusingantioxidantsuchastocopherol,gallicacidandascorbicacid.
❖Thefollowingaresomeofthequalitiesofanidealanti-oxidant:
✓Itshouldbereadilysolubleinthemedium.
✓Itshouldbeeffectiveinlowconcentration.
✓Itshouldbenontoxic.
✓Itshouldbenonirritant.
✓Itshouldbecolorless,odorlessandtasteless.

48. 48
Flavours
✓VanillinisagoodFlavouringagentforliquidparaffinemulsion.
✓BenzaldehydeisgenerallyusedasFlavouringagentsforcod-liveroilemulsion.
✓AcombinationofFlavouringandsweeteningagentsprovidesgreaterpalatabilitytoemulsion.

49. 49
Preparation of Emulsion
✓Thefollowingmethodsarecommonlyusedforthepreparationofemulsionsonsmallscale:
1.DrygumMethod
2.WetgumMethod
3.BottleMethod
4.OtherMethod

50. 50
Dry Gum Method
✓Measuretherequiredquantityofoilindrymeasureandtransferitintoadrymortar.
✓AddthecalculatedquantityofgumacaciaintoitandtrituraterapidlysoastoformauniformMixture.
✓Addrequiredquantityofwaterandtrituratevigorouslytillaclickingsoundisproducedandtheproduct
becomeswhiteornearlywhiteduetothetotalinternalreflectionoflight.
✓Theemulsionproducedatthisstageisknownasprimaryemulsion.
✓Addmoreofwatertoproducerequiredvolume.

51. 51
Wet Gum Method
✓Calculatethequantityofoil,waterandgumrequiredforpreparingtheprimaryemulsion.
✓Powderthegumacaciainamortar.Addwaterandtriturateitwithgumsoastoformamucilage.
✓Addrequiredquantityofoilinsmallportionswithrapidtriturationuntilaclickingsoundisproducedandthe
productbecomeswhiteornearlywhite.Atthisstagetheemulsionisknownasprimaryemulsion.
✓Addmoreofwaterinsmallportionstotheprimaryemulsionwithtriturationtoproducetherequiredvolume.
Stirthoroughlysoastoformauniformemulsion.
✓Transfertheemulsiontoabottle,cork,labelanddispense.

52. 52
Bottle Method
✓Measuretherequiredquantityoftheoilandtransferintoalargebottle.Addtherequiredquantityof
powderedgumacacia.
✓Shakethebottle,untiltheoilandgumaremixed.
✓Addthecalculatedamountofwaterallatonce.
✓Shakethemixturetoformaprimaryemulsion.
✓Addmoreofwaterinsmallportionswithconstantagitationtoproducetherequiredvolume.

53. 53
Stability of Emulsion
✓Anemulsionissaidtobestableifitremainsassuchafteritspreparation,i.e.,dispersionglobulesare
uniformlydistributedthroughoutthedispersionmediumduringitsstorage.
✓Theemulsionshouldbechemicallystableandthereshouldnotbeanybacterialgrowthduringitsshelflife.
✓Thefollowingthreechangesusuallyoccursduringthestorageofanemulsion:
1.Cracking
2.Creaming
3.Phaseinversion

54. 54
1. Cracking
✓Crackingmeanstheseparationoftwolayersofdisperseandcontinuousphase,duetothecoalescenceof
dispersephaseglobuleswhicharedifficulttoredispersebyshaking.
✓Crackingmayoccursduetofollowingreasons:
1.Byadditionofemulsifyingagentsofoppositetype
2.Bydecompositionorprecipitationofemulsifyingagents
3.Byadditionofacommonsolvent
4.ByMicroorganisms
5.Changesintemperature
6.Bycreaming

55. 55
By addition of emulsifying agents of opposite type
✓Soapsofmonovalentmetalsproduceo/wtypeemulsionswhereassoapsofdivalentmetalproducew/o
typeemulsions.
✓Buttheadditionofmonovalentsoaptoadivalentsoapemulsionoradivalentsoaptoamonovalentsoap
emulsionleadstocrackingofemulsion.
By decomposition or precipitation of emulsifying agents
✓Whenanacidisaddedtoanalkalisoapemulsion,itcausesthedecompositionofanemulsifyingagents
andthusleadstocrackingofanemulsion.
✓Similarly,whensodiumchlorideisaddedtosodiumorpotassiumsoapemulsion,itleadstotheprecipitation
ofemulsifyingagentsandthuscrackingofemulsiontakeplace.

56. 56
By addition of a common solvents
✓Whenasolventisaddedtoanemulsionwhichiseithermisciblewithordissolvethedispersedphase,the
emulsifyingagentandcontinuephase,thereisformationofonephaseoracleansolution.
✓Thisleadstocrackingofanemulsion
By Microorganisms
✓Ifemulsionsarenotstoredproperly,theymaydevelopbacterialandmouldgrowth.Thismayleadsto
destructionofemulsifyingagentsandcausecrackingofemulsion.
✓Therefore,itisdesirablethatallemulsionswhicharerequiredtobestoredforalongperiodshouldbe
suitablypreserved.

57. 57
Changes in temperature
✓Whenemulsionarestoredforalongtime,anincreaseintemperaturemayreducetheviscosityofthe
emulsionandencouragecreaming.
✓Whenemulsionsarestoredataverylowtemperature,freezingofitswatercontentintoiceandmeltingof
aniceandshakingmayreformtheemulsion.
By Creaming
✓Acreamyemulsionismoreliabletocrackthanahomogenousemulsion.Itistherefore,necessarytotake
stepstoretardcreamingasfaraspossible.

58. 58
2. Creaming
✓Creamingmaybedefinedastheupwardmovementofdispersedglobulestoformathicklayeratthe
surfaceoftheemulsion.
✓Creamingisatemporaryphasebecauseitcanbere-distributedbymildshakingorstirringtogetagaina
homogenousemulsion.
✓Asfaraspossiblecreamingofanemulsionshouldbeavoidedbecauseitmayleadtocrackingwith
completeseparationoftwophase
✓Accordingtostoke’slaw,therateofcreamingdependsonthenumberoffactorswhichcanbeexplainedby
followingequation:
??????=
2??????2??????1−??????2??????
9??????

59. 59
✓Accordingtostoke’slaw,therateofcreamingdependsonthenumberoffactorswhichcanbeexplainedby
followingequation:
??????=
2??????2??????1−??????2??????
9??????
Where,
V=Rateofcreaming
R=Radiusofglobules
D1=Densityofdispersedphase
D2=densityofcontinuousphase
G=Gravitationalphase
N=Viscosityofthedispersionmedium

60. 60
1.Radiusofglobules:
✓Therateofcreamingisdirectlyproportionaltotheradiusoftheglobules.Largerthesizeofglobulesthe
morewillbecreamingandsmallerthesizeoftheglobules,lesserwillbecreaming.Thesmallglobulesrise
lessquicklythanlargeglobules.
✓Hence,creamingcanbereducedbyreducingsizeofglobulesbypassingtheemulsionthrougha
homogenizer.
2.Differenceindensityofdispersephaseandcontinuousphase:
✓Therateofcreamingdependsuponthedifferencebetweenthedensitiesofthedispersephase&
continuousphase.
✓Greaterthedifference,morewillbethecreaming.Thisdifferencecanbereducedbutitisnotdesirable
becauseitisnotrequiredtherapeutically.

61. 61
3.Viscosityofthedispersed:
✓Therateofcreamingisinverselyproportionaltotheviscosityofthedispersedmedium.
✓Theviscositycanbeincreasedbyaddingtragacanthandmethylcellulose,buttoomuchviscosityis
undesirablebecauseitmaybecomedifficulttoredispersethematerialswhichhavesettledatthebottom.
✓Moreover,itisdifficulttopourtheemulsionfromthecontainer.
4.Storagecondition:
✓Theemulsionshouldbestoredinacoolplacebecausetheriseintemperaturereducestheviscositywhich
mayleadstocreaming.
✓Thefreezingshouldbeavoidedbecauseitmayleadstocracking.

62. 62
3. Phase inversion
✓Phaseinversionmeansthechangeofonetypeofemulsionintotheothertypei.e.,oilinwateremulsion
changesintowaterinoilemulsion.
✓Itmaybeduetofollowingreason:
1.Bytheadditionofanelectrolyte
2.Bychangingthephasevolumeratio
3.Bytemperaturechange
4.Bychangingtheemulsifyingagents
✓Thephaseinversioncanbeminimizedbykeepingtheconcentrationofdispersephasebetween30-60%,
storingtheemulsioninacoolplaceandusingproperemulsifyingagentsinproperconcentration.

63. 63
Storage of Emulsion
✓Theemulsionshouldbestoredincontainershavinganadequateairspaceabovetheemulsion,soasto
permitadequateshakingbeforeitsuse.
✓Theemulsionwhichareuseforinternal,shouldbepackedincomparativelywidemouthbottlesothatitis
easytoremoveitwithoutanydifficulty.
✓Asecondarylabel“ShakeWellBeforeuse”isrequiredtobefixedonthecontainer.
✓Anemulsionshouldbestoredinairtightclosedcontainer,protectedfromlight,frrzingandexcessheat.
✓Theyarerequiredtobestoredinacoolplace.

64. 64
EMULSION SUSPENSION
It is a heterogeneous mixture of two immiscible
liquids
It is a heterogeneous mixture
Dispersed particle do not settle on standing Dispersed particle settle on standing
Dispersed particle size 1 to 1000nm Dispersed particle size more than 1000nm
Particle are not visible through the naked eye Particle are visible through the naked eye
It can not be separated by filtration It can be separated by filtration
Dispersed in solid, liquid or gas Dispersed in liquid
Emulsifying agents are required Suspending agent are required
Freezing should be avoided during as it leads to
cracking
Freezing should be avoided during as it leads to
aggregation
DIFFERENCE BETWEEN EMULSION & SUSPENSION