1.Unit processes used in pharmacy- INTRODUCTION (1).pdf

Pharmaceutical Processing is the process of drug manufacturing and can be broken down into a range of unit operations, such as blending, granulation, milling, coating, tablet pressing, filling, and others.

1. Associate Professor & Research coordinator,
Department of Pharmaceutics, KIU-WC.

2. PharmaceuticalProcessingistheprocessofdrugmanufacturingandcanbebrokendowninto
arangeofunitoperations,suchasblending,granulation,milling,coating,tabletpressing,filling,and
others.
UnitOperations:Unitoperationisabasicstepinaprocess.Unitoperationsinvolvea
physicalchangeorchemicaltransformationsuchasseparation,crystallization,
evaporation,filtration,polymerization,iso-merization,andotherreactions.
Forexample,inmilkprocessing,homogenization,pasteurization,chilling,and
packagingareeachunitoperationswhichareconnectedtocreatetheoverallprocess.A
processmayrequiremanyunitoperationstoobtainthedesiredproductfromthestarting
materials.
1.Fluidflowprocesses:includingfluidstransportation,filtration,andsolidsfluidization.
2.Heattransferprocesses:includingevaporation,condensation,andheatexchange.
3.Masstransferprocesses:includinggasabsorption,distillation,extraction,adsorption,and
drying.
4.Thermodynamic processes:includinggasliquefaction,andrefrigeration.
5.Mechanicalprocesses:includingsolidstransportation,crushingandpulverization,and
screeningandsieving.
Unit Operations-Classifications
INTRODUCTION

3. •A''unitprocess''isoneormoregroupedoperationsina
manufacturingsystemthatcanbedefinedandseparatedfrom
others.
•Unitprocessinvolvesachemicalchangeorsometimesitis
referredaschemicalchangesalongwithPhysicalChangeleading
tothesynthesisofvarioususefulproduct.
Example:Hydrogenation,oxidation,nitrationetc.
Unit process

4. History and Background
1)Arthur Dehon Little
propoundedtheconceptof"unit
operations"toexplainindustrial
chemistryprocessesin1916.
2)In1923,WilliamH.Walker,WarrenK.LewisandWilliamH.
McAdamswrotethebook“ThePrinciplesofChemical
Engineering”andexplainedthatthevarietyofchemical
industrieshaveprocesseswhichfollowthesamephysical
laws.
Importance of unit operation

5. Drug:
Adrugproductconsistsoftherapeutics(API)andexcipientscombinedinadelivery
system.
Adrugproduct’ssuccessliesinitsabilitytodeliverthedrugatacertainrateina
certainenvironmentinthebody.

6. Classification

7. Chapter -1
Flow of Fluid
Fluids -The substances which have ability to flow.
Solid –movement but size, shape does not charge,
Liquid–movement and deformation in shape.
Gas–Same
So, liquid & gas are fluids.
Fluid pressure: The pressure which apply by the fluid. Also known as “Hydrostatic pressure”.
Pressure =Force /Area = F/A= mass (m) ×gravitational (g) / Area (A)
Thesolutiontoafluiddynamicsproblemtypicallyinvolvesthecalculationofvariouspropertiesofthefluid,
suchasflowvelocity,pressure,density,andtemperature,asfunctionsofspaceandtime.
Thermodynamic equation:
P=
wherepispressure,ρisdensity,Ttheabsolutetemperature,whileRuisthegasconstantand
Mismolarmassforaparticulargas.
ρRuT
M
Reynoldsnumber:Itisusedformeasurementandtypeofflowdetermination.
Re=D×u×densityofliquid/Viscosityoffluid
D=diameterofpipe,u=Averagevelocity
WhenRe<2000thenflowislaminarorviscousorstreamline
Re>4000thenflowisturbulent
Reis2000–4000thenflowislaminarorturbulent
Reynolds number is used to predict
the nature of the flow.
Bernoulli's equation:
Used in the measurementof rate of fluid flow.
It applied in the working of the centrifugal pump, in this “ kinetic energy is converted in to pressure”.

8. Chapter 2
Heat and Mass Transfer
Heat transfer is the movement of heat energy from one substance to another.
•Heat will continue to move until both substances are the same temperature.
•The greater the difference in temperature between the substances,
the faster the heat will transfer.

9. Chapter 3 Filtration
Filtration,theprocessinwhichsolid
particlesinaliquidorgaseousfluidareremovedby
theuseofafiltermediumthatpermitsthefluid
topassthroughbutretainsthesolidparticles.
Eithertheclarifiedfluidorthesolid
particlesremovedfromthefluidmaybethe
desiredproduct.
1.Surfacefiltration(Screenfiltration):E.g.,Membranefiltration
2.Depthfiltration:E.g.,Ceramicfiltration,Sinteredfiltration
3.Cakefiltration:E.g.,Filtercakemadefromdiatomite
Types of Filtration

10. 3

13. Chapter 4 Centrifugation
Centrifugationisamethodofseparating
moleculeshavingdifferentdensitiesby
spinningtheminsolutionaroundanaxis
(inacentrifugerotor)athighspeed.
Itisoneofthemostusefulandfrequently
employedtechniquesinthemolecular
biologylaboratory.
Centrifugation

16. Chapter 5 Size Reduction
Sizereductionisaprocessinwhichtheparticlesizeofasolidismadesmaller.
Thetermsizereductionisappliedtowaysinwhichparticlesofsolidsarecutorbroken
intosmallerpieces.
1.Hardness:Harderthematerial,moredifficulttoreduceitssize.
2.Toughness:Softbuttoughmaterialcreatesprobleminsizereductionanditstoughnessisreducedby
decreasetemperature.
3.Stickness:Gumandresinoussubstancescauseprobleminsizereduction.
4.Moisturecontent:<5%moisturesuitablefordrygrindingand>50%forwetgrinding.
Factors affecting size reduction

18. Chapter 6 Mixing of Solids
Definition:Itisaunitoperationinwhichtwoormorethantwocomponentsin
separatelyorroughlymixed.
Mixing Equipments
1. Liquid mixers 3. Semi-solid mixers
A. Agitator mixers
B. Shear mixers

19. Chapter 7 Extraction
Extractionisthemethodofremovingactiveconstituentsfromasolidor
liquidbymeansofliquidsolvent.
Theseparationofmedicinallyactiveportionsofplantoranimaltissues
fromtheinactiveorinertcomponentsbyusingselectivesolvents.
Extractsarepreparedbyusingethanolorothersuitablesolvent.
Extract:Extractscanbedefinedaspreparationsofcrudedrugswhich
containalltheconstituentswhicharesolubleinthesolvent.
Marc:Solidresidueobtainafterextraction.
Menstrum:Solventusedforextraction.
Inthismethodthewantedcomponentsaredissolvedbytheuseofselective
solventsknownasmenstrum&undissolvedpartisamarc.Aftertheextraction
unwantedmatterisremoved.

20. Chapter 8 DISTILLATION
Itisdefinedastheseparationofthecomponentsoftheliquidmixturebyprocess
involvingvaporizationandsubsequentcondensationatanotherplace.
Psolution=Xsolvent. Psolvent
Raoult’slaw:Itstatesthatasolvent'spartialvapour
pressureinasolution(ormixture)isequaloridenticaltothe
vapourpressureofthepuresolventmultipliedbyitsmole
fractionintheatgiventemperature.
Psolution=Vaporpressureofthesolution
Xsolvent=molefractionofthesolvent
Psolvent=vaporpressureofthepuresolvent.
Idealsolutionobeys(behaves)Raoult’slaw.
Raoult’slawisobeyedbyonlyafewsolutionofliquidin
liquids.
Examplesarebenzene,toluene,n-hexane,n-heptane,ethyl
bromide,ethyliodide.
Dalton’slaw:Itstatesthatthetotalpressurepofmoistairisthesumofpartial
pressuresofdryairp
aandwatervaporp
v: p=p
a+p
v

21. Chapter 9 Evaporation
Defined asa process by which a liquid is transformed into vapour.

22. Chapter 10 Crystallization
Crystallizationisthephysicaltransformation(phasetransition)ofaliquid,solution,
orgastoacrystal,whichisasolidwithanorderedinternalarrangementofmolecules,
ions,oratoms.

23. Chapter 11 Drying
Dryingistheprocessofusingevaporationtoremovewaterfromasolution,
suspension,orothersolid-liquidmixture.
Inadditiontosolids,theprocesscanalsobeusedtoremovewaterfromliquidsor
gases.

24. Formulation and pre-formulation development
Beforeadrugcanbemanufacturedatanyscale,muchworkgoesinto
theactualformulationofthedrug.
Formulationdevelopmentscientistsmustevaluateacompoundfor
uniformity,stabilityandmanyotherfactors.
Aftertheevaluationphase,asolutionmustbedevelopedtodeliverthedrug
initsrequiredformsuchassolid,semi-solid,immediateorcontrolled
release,tablet,capsule.

25. Powder blending
Inthepharmaceuticalindustry,awiderangeofexcipientsmaybeblended
togethertocreatethefinalblendusedtomanufacturethesoliddosageform.
Therangeofmaterialsthatmaybeblended(excipients,API),presentsanumberof
variableswhichmustbeaddressedtoachieveproductsofacceptableblend
uniformity.
Thesevariablesmayincludetheparticlesizedistribution(includingaggregatesor
lumpsofmaterial),particleshape(spheres,rods,cubes,plates,andirregular),
presenceofmoisture(orothervolatilecompounds),andparticlesurfaceproperties
(roughness,cohesivity).

26. Milling
Duringthedrugmanufacturingprocess,millingisoftenrequiredinorder
toreducetheaverageparticlesizeinadrugpowder.
Thereareanumberofreasonsforthis,including
Increasinghomogeneityanddosageuniformity,
Increasingbioavailability,and
Increasingthesolubilityofthedrugcompound.

27. Granulation
Granulationcanbethoughtofastheoppositeofmilling;
Itistheprocessbywhichsmallparticlesareboundtogethertoformlargerparticles,
called“granules”.
Granulationisusedforseveralreasons.
Granulationpreventsthe"de-mixing"ofcomponentsinthemixture,bycreatinga
granulewhichcontainsallofthecomponentsintheirrequiredproportions,
Improvesflowcharacteristicsofpowders(becausesmallparticlesdonotflowwell),and
Improvescompactionpropertiesfortabletformation.

28. Hot melt extrusion
Hotmeltextrusionisutilizedinpharmaceuticalsolidoraldoseprocessingtoenable
deliveryofdrugswithpoorsolubilityandbioavailability.
Hotmeltextrusionhasbeenshowntomolecularlydispersepoorlysolubledrugsina
polymercarrierincreasingdissolutionratesandbioavailability.
Theprocessinvolvestheapplicationofheat,pressureandagitationtomixmaterials
togetherand'extrude'themthroughadie.
Twin-screwhighshearextrudersblendmaterialsandsimultaneouslybreakupparticles.
Theresultingparticlescanbeblendedandcompressedintotabletsorfilledinto
capsules.