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1、PHARMACEUTICALENGINEERINGMixingDr.BhawnaBhattDelhiInstituteofPharmaceuticalScienceandResearchSector–3,PushpViharNewDelhiProf.S.S.AgrawalPrincipalDelhiInstituteofPharmaceuticalScienceandResearchSector–3,PushpViharNewDelhi(24-08-2007)CONTENTSIntroductionObjectiv
2、esTypesofMixturesMechanismRateofMixingTheoryofMixingLiquidmixingLiquidmixersSolid-SolidMixingPowdermixersMixingsemi-solidsMixersforsemi-solidsKeywordsLiquid-liquidmixing,solid-solidmixing,solid-liquidmixing,Propellers,Doubleconemixers,Rollermills,Sigmablender,
3、Colloidmill.1IntroductionMixingisoneofthemostcommonpharmaceuticaloperations.Itisdifficulttofindapharmaceuticalproductinwhichmixingisnotdoneatonestageortheotherduringitsmanufacturing.Mixingmaybedefinedastheprocessinwhichtwoormorethantwocomponentsinaseparateorro
4、ughlymixedconditionaretreatedinsuchawaysothateachparticleofanyoneingredientliesasnearlyaspossibletotheadjacentparticlesofotheringredientsorcomponents.Thisprocessmayinvolvethemixingofgases,liquidsorsolidsinanypossiblecombinationandinanypossibleratiooftwoormorec
5、omponents.Mixingofagaswithanothergas,mixingofmisciblelowviscosityliquidsandmixingofahighlysolublesolidwithalowviscosityliquidtoeffectdissolutionarerelativelysimpleascomparedtothemixingofgaseswithliquids,mixingofliquidsofhighviscositythoughmiscible,mixingoftwoi
6、mmiscibleliquidssuchasaqueousandoilysolutionstoformemulsions,mixingofsolidswithliquidswhentheproportionofsolidsishighandmixingofsolidswithsolids,specializedequipmentsarerequiredfortheseoperations.Someoftheexamplesoflargescalemixingpracticedinpharmacyare:∑Mixin
7、gofpowdersinvaryingproportionspriortogranulationortabletting∑Drymixingofthematerialsfordirectcompressionintablets∑Dryblendingofpowdersincapsulesandcompoundpowders(insufflations).∑Blendingofpowdersincosmeticsinthepreparationoffacepowders,toothpowders∑Dissolutio
8、nofsolublesolidsinviscousliquidsfordispensinginsoftcapsulesandinthepreparationofsyrups∑Mixingoftwoimmiscibleliquidsforpreparationofemulsions.Dependingontheflowpropertiesofmaterials
