2-6-Extraction Processes of NaturalDrugs.pdf

Pharmacognosy

1. EXTRACTION PROCESSES
Dr. L.T. Muungo, PhD
1

2. Extraction Process - This unit will be covered under the following subject
topics to meet the objectivity of plants as source of medicinal chemical
agents but not exhaustively:
❑Introduction
✓Previewofmedicinalplantsandphytochemicals
✓Factorialconsiderationsofextractionprocess
✓Idealpropertiesofextractivesolvent
✓Advantagesanddisadvantagesofextractivesolvents
❑TheoryofExtraction
✓Mechanismsofextraction
✓Parameterconsiderationforextractionmethods
✓Sizereduction
✓Extractivesolventdrugpenetrationprocess
✓Stepsofextractionprocess
❑MethodsofExtraction
✓Infusion
✓Decoction
✓Digestion
✓Maceration
✓Percolation
✓Continueshotextraction
✓Supercriticalfluidextraction
✓Countercurrentextraction
✓Microwaveassistedextraction
✓Ultrasonication-AssistedExtraction

3. Topical Sub-titles: This subject topic has been compiled to reflect the
following on physicochemical characteristics of modern extractive process for
natural resourced drug agents:
❑Introduction
❑Traditional / Classical Extraction Techniques
✓Maceration Extraction Process
✓Percolation Extraction Process
✓Infusion Extraction Process
✓Decoction Extraction Process
❑Modern / Sophisticated Extraction Techniques
✓Ultra-sound Extraction
✓Accelerated solvent extraction (ACE)
✓Super Critical Fluid Extraction
✓Solid phase Extraction
✓Fractional Extraction Processes
✓Chromatographic Extraction Process
✓Spectroscopic Extraction Process
✓Electrophoresis Extraction Process
✓Digestion Extraction Process
✓Microwave-assisted extraction (MAE)
✓Ultrasonication-assisted extraction (UAE)
✓Counter-Current Extraction
✓Phytonics Extraction Process
✓Ionic liquid Mediated Extraction (Ils)
✓Pressurized liquid/fluid Extraction (PLE)
✓Enzyme-assisted extraction

4. ✓Maceration Extraction - Process: Maceration involves soaking the
plant material in a solvent at room temperature. Example: Extraction
of alkaloids from plants using ethanol.
✓Percolation Extraction - Process: The solvent continuously passes
through a bed of plant material, usually at a controlled rate.
Example: Extraction of tannins from bark using water.
✓Infusion Extraction - Process: Plant material is soaked in hot or
cold water to extract the active constituents. Example: Making herbal
teas.
✓Decoction Extraction - Process: Plant material is boiled in water for
a specified period. Example: Extraction of glycosides from roots.
✓Ultra-sound Extraction - Process: Ultrasonic waves are used to
agitate the plant material in the solvent, increasing extraction
efficiency. Example: Extraction of essential oils from flowers using
ethanol.

5. ✓Accelerated Solvent Extraction (ASE) - Process: Uses high
temperature and pressure to increase the efficiency of solvent
extraction. Example: Extraction of polyphenols from leaves.
✓Supercritical Fluid Extraction - Process: Uses supercritical fluids
(e.g., CO₂) to extract phytochemicals. Example: Extraction of
caffeine from coffee beans using supercritical CO₂.
✓Solid Phase Extraction (SPE) - Process: Uses a solid adsorbent to
trap and then release phytochemicals from a liquid sample. Example:
Extraction of flavonoids from plant extracts.
✓Fractional Extraction - Process: Sequentially uses different solvents
of increasing polarity to fractionate the extract. Example:
Fractionation of complex plant extracts to isolate specific
compounds.
✓Chromatographic Extraction - Process: Separation of
phytochemicals based on their affinity to stationary and mobile
phases. Example: Extraction of chlorophyll from leaves using
column chromatography.

6. ✓Spectroscopic Extraction - Process: Identifies and quantifies
phytochemicals using spectroscopic methods after extraction.
Example: Extraction and analysis of curcumin from turmeric using
UV-Vis spectroscopy.
✓Electrophoresis Extraction - Process: Uses an electric field to
separate phytochemicals based on their charge and size. Example:
Extraction and separation of plant proteins.
✓Digestion Extraction - Process: Involves heating plant material in a
solvent for a prolonged period. Example: Extraction of resin from
plant material using organic solvents.
✓Microwave-Assisted Extraction (MAE) - Process: Uses microwave
energy to heat solvents in contact with plant materials to enhance
extraction. Example: Extraction of essential oils from spices.
✓Ultrasonication-Assisted Extraction (UAE) - Process: Uses
ultrasonic energy to disrupt plant cell walls and enhance extraction.
Example: Extraction of antioxidants from berries.

7. ✓Counter-Current Extraction - Process: Two immiscible liquids
flow in opposite directions to extract compounds efficiently.
Example: Extraction of alkaloids from plant material using water and
chloroform.
✓Phytonics Extraction - Process: Uses fluoro-substituted
hydrocarbons under mild conditions to extract phytochemicals.
Example: Extraction of fragrances from flowers.
✓Ionic Liquid Mediated Extraction (Ils) - Process: Utilizes ionic
liquids as solvents to extract phytochemicals. Example: Extraction of
alkaloids from medicinal plants.
✓Pressurized Liquid/Fluid Extraction (PLE) - Process: Uses high
pressure to maintain the solvent in a liquid state above its boiling
point. Example: Extraction of bioactive compounds from herbs.
✓Enzyme-Assisted Extraction - Process: Uses enzymes to break
down cell walls and enhance the release of phytochemicals.
Example: Extraction of pectin from citrus peels using pectinase
enzyme.

8. The above briefly stated methods offer
a variety of techniques for efficiently
extracting bioactive compounds from
plant materials, each with specific
advantages depending on the nature of
the phytochemicals and the plant
matrix.

9. Medicinalplants
✓Medicinalplantsconstituteaneffectivesourceofboth
traditionalandmodernmedicines
✓Herbalmedicinehasbeenshown tohavegenuineutility
✓About80%ofruralpopulationdependsonitasprimary
healthcare.[WHO, (2005)]
Introduction:

10. Medicinalplantsaretherichest bio-resource
❖drugsof traditionalsystemsofmedicine
❖modernmedicines
❖nutraceuticals
❖foodsupplements
❖folkmedicines
❖pharmaceuticalintermediates
❖chemical entitiesforsyntheticdrugs

11. ❖Naturalbioactivecompoundsfoundindifferentpartsofplant
(fruit,flower, stem,leaf,root)
❖Provide definite physiological action onthehumanbody
❖Bioactivesubstancesincludetannins,alkaloids,carbohydrates,
terpenoids,steroidsand flavonoids
❖Widelyusedinthehumantherapy,veterinary,agriculture,
scientificresearch and countless other areas
❖Have inhibitoryeffectsonall typesofmicroorganismsinvitro
Phytochemicals

12. Extraction
………istheseparationofmedicinallyactiveportionsof
planttissuesusingselectivesolventsthroughstandardprocedures
Thebasicparametersinfluencingthequalityofanextract
•Plantpartusedasstartingmaterial
•Solventusedforextraction
•Extractionprocedure

13. Choiceofsolvents
Successfuldeterminationofbiologicallyactive
compoundsdependsonthetypeofsolventusedinthe
extractionprocedure
Propertyofagoodsolventinplantextraction
•Lowtoxicity
•Easeofevaporation atlowheat
•Promotion ofrapidphysiologicabsorptionoftheextract
•Preservativeaction

14. Solventsusedforactivecomponent extraction
Water
Anthocyanins
Starches
Tannins
Saponins
Terpenoids
Polypeptides
Lectins
Ethanol
Tannins
Polyphenols
Polyacetylenes
Flavonols
Terpenoids
Sterols
Alkaloids
Methanol
Anthocyanins
Terpenoids
Saponins
Tannins
Xanthoxyllines
Totarol
Quassinoids
Lactones
Flavones
Phenones
Polyphenols
Chloroform
Terpenoids
Flavonoids
Ether
Alkaloids
Terpenoids
Coumarins
Fattyacids
Acetone
Phenol
Flavonols

15. 2
➢Extractionmaybedefinedastheremovalofsolubleconstituents
fromasolidorliquidorsemi-solidwithmeansofsuitablesolvent.
➢Treatmentoftheplantoranimaltissueswithappropriatesolvent-
whichwoulddissolvethemedicinallyactiveconstituents.
➢Extractionisthemethodofremovalofasolublefractionintheform
ofasolutionfromaninsolublematrixwiththehelpofasuitable
solvent.
➢Soluble fractions: a solid or liquid
➢Insoluble matrix: powder form, openly porous or non porous or
cellular with selective permeable cell walls as in case of vegetable

16. Example:Boilingof tea
Theobromine,CaffieneandTannins
16

17. ➢Plant constituents are usually contained inside the
cells. Therefore, the solvent used for extraction must
diffuseinto thecell todissolvethedesiredcompounds.
➢An equilibriumisestablishedbetweenthesolute
inside the cells and the solvent surrounding the
fragmentedplanttissues.
17

18. Definitions
18
➢Menstrum:The solvent capable of penetrating the cell wall of crude drugs
and dissolves all types of active constituents from it is called as Menstruum.
There are two types of menstruum.
➢Marc: The inert insoluble substance left after
extraction is called as Marc.
➢Extractives: Concentrated preparations of vegetableor
animal-evaporationofallornearly all solvent
➢Tinctures: are alcoholic or hydro-alcoholic solutions
prepared fromvegetablematerialorfrom chemical
substances.E.g.belladonatincture

19. Menstrum:Polarandnon-polar
19

20. Factorsaffectingextractionprocess
•Natureofdrug
•Natureofextractingsolvent
•Solventtemperature
•Ratioofsolventtoplantmaterial
•Particlesize
•Durationofextraction

21. Thefactorsaffectingthechoiceofsolvent
•Quantityofphytochemicalstobeextracted
•Rateofextraction
•Diversityofdifferent inhibitorycompounds extracted
•Ease ofsubsequent handlingof theextracts
•Toxicityofthesolventinthebioassayprocess
•Potentialhealthhazardoftheextractants

22. IdealPropertiesofSolvent
22
➢Be highlyselectiveforthecompoundtobeextracted.
➢Haveahighcapacityforextraction.
➢Notreactwiththeextractedcompound or withother
compoundsinthe plantmaterial.
➢Havealow price
➢Beharmlesstomanandtothe environment
➢Becompletelyvolatile
➢Thegenerallyused solventsincludes:Water,ether,alcohol,
chloroform.

23. 59
Factors affectingthechoiceofextraction
process
1.Characterofdrug
➢Knowledge ofpharmacognosy–maceration
processifdrug issoft,percolationprocessused
whendrugishard andtough
2.Therapeuticvalueofthe drug
➢when the drug has high therapeutic value,
maximumextractionisrequired,sopercolation
processis usede.g.Belladona.
3.Costofdrug
➢costly drugsareextracted bypercolationprocess,
whereascheapdrugsareextractedbymaceration
process.

24. Factorsaffectingthe choiceofextraction process
4.Stabilityofdrug
➢Thermolabile drugs-macerationorpercolationshould
bedone.
➢Nohotextractionprocessshouldbe carriedout.
5.Solvent
➢Macerationprocessrecommended-ifwaterisusedas
solvent.
➢Percolationprocess-non-aqueoussolvents.
24

25. Factorsaffectingthe choice ofextraction process
6.Concentrationofproduct
➢Thediluteproductssuchastincturescanbemadeby
usingmacerationorpercolationprocess,dependingon
otherfactors.
➢For semi-concentrated preparations, such as
concentratedinfusions,doubleortriplemaceration
processcanbeused.
➢Theliquidextractsordryextractsordryextracts
whichareconcentratedpreparationsarepreparedby
usingpercolationprocess.
25

26. Advantagesofwaterasmenstrum
➢Readilyavailable
➢Economical
➢Good solventaction formanyplantconstituents
➢Used with othersolvents
26

27. Disadvantagesofwaterasasolvent
27
➢Most active plant constituents are complex organic
chemical which are less solubleinwater
➢Plant constituents-sugars, gums, starches, colouring
agents,tanninsare easily extractedbywater,however
are not desirable component sometimes and may
interfere with clarityofthepreparation
➢Aqueouspreparations-growthformoulds,yeastsand
bacteria.Preservatives-alcohol
➢Water-hydrolysisofmanysubstances
➢Verydifficulttoremovethesolvent

28. Theoryofextraction
28
➢Suitablesizereduction
➢Penetrationofdrugby thesolvent
➢Solutionofthe solublematterwithinthecells
➢Escape of dissolved material through the cell walls and
throughtheboundarylayersurroundingtheparticles
➢Separationofthesolutionandexhausted drug

29. MechanismofExtraction
•Therefore,solventusedforextractionmustdiffuseintothecelltodissolvethedesired
compoundswhereuponthesolutionmustpassthecellwallintheoppositedirectionand
mixwiththesurroundingliquid
•Anequilibriumisestablishedbetweenthesoluteinsidethecellsandthesolvent
surroundingthefragmentedplanttissues
•Dissolutionofextractivesubstancesoutofdisintegratedcells.
•Dissolutionofextractivesubstancesoutofintactplantcellbydiffusion(requiressteeping
andswelling)
•Penetrationofthesolventintotheplantcellsandswellingofthecells.
•Diffusionofthedissolvedextractivesubstancesoutofthecell.
•Plantconstituentsareusuallycontainedinsidethecells.

30. ParametersforSelectinganAppropriateExtractionMethod
•Authenticationofplantmaterialshouldbedonebeforeperformingextraction.Any
foreignmattershouldbecompletelyeliminated.
•Usetherightplantpartand,forqualitycontrolpurposes,recordtheageofplant
andthetime,seasonandplaceofcollection.
•Conditionsusedfordryingtheplantmateriallargelydependonthenatureofits
chemicalconstituents.Hotorcoldblowingairflowfordryingisgenerally
preferred.Ifacrudedrugwithhighmoisturecontentistobeusedforextraction,
suitableweightcorrectionsshouldbeincorporated.
•Grindingmethodsshouldbespecifiedandtechniquesthatgenerateheatshould
beavoided
asmuchaspossible.
•Powderedplantmaterialshouldbepassedthroughsuitablesievestogetthe
requiredparticlesofuniformsize.

31. Natureofconstituents:Ifthetherapeuticvalueliesinnon-polarconstituents,a
non-polarsolventmaybeused.Forexample,lupeolistheactiveconstituentof
Crataevanurvalaand,foritsextraction,hexaneisgenerallyused.
Likewise,forplantslikeBacopamonnieriandCentellaasiatica,theactive
constituentsareglycosidesandhenceapolarsolventlikeaqueousmethanolmay
beused.
Iftheconstituentsarethermolabile,extractionmethodslikecoldmaceration,
percolationandCCEarepreferred.

32. Forthermostableconstituents,Soxhletextraction(ifnonaqueoussolvents
areused)anddecoction(ifwateristhemenstruum)areuseful.
Suitableprecautionsshouldbetakenwhendealingwithconstituentsthat
degradewhilebeingkeptinorganicsolvents,e.g.flavonoidsand
phenylpropanoids.
Incaseofhotextraction,higherthanrequiredtemperatureshouldbe
avoided.Someglycosidesarelikelytobreakuponcontinuousexposureto
highertemperature.

33. Standardizationoftimeofextractionisimportantforexample
insufficienttimemeansincompleteextraction.
Iftheextractiontimeislonger,unwantedconstituentsmayalsobe
extracted.Forexample,ifteaisboiledfortoolong,tanninsare
extractedwhichimpartastringencytothefinalpreparation.

34. •Thenumberofextractionsrequiredforcompleteextractionisasimportantasthe
durationofeachextraction.
•Thequalityofwaterormenstruumusedshouldbespecifiedandcontrolled.
•Concentrationanddryingproceduresshouldensurethesafetyandstabilityofthe
activeconstituents.Dryingunderreducedpressure(e.g.usingaRotavapor)iswidely
used.
•Lyophilization,althoughexpensive,isincreasinglyemployed.
•Thedesignandmaterialoffabricationoftheextractorarealsotobetakeninto
consideration.
•Analyticalparametersofthefinalextract,suchasTLCandHPLCfingerprints,should
bedocumentedtomonitorthequalityofdifferentbatchesoftheextracts.

35. Theflowchartof
medicinalplantstudy
and positionof
extractiontechniques

37. 1.Sizereduction
37
➢Properextraction-maximumsurfaceareaofcontact
wouldbedesirable.
➢Individualcellsize-bestoption
Problemswithcellularlevelsizereduction
➢Itmaycausedecompositionofconstituentsormaylead
tolossofvolatilematerials.
➢Veryfineparticlesmaynotformgoodsuspensionas
theywouldn’tsedimentatthedesiredrateandparticle
sizeifreducedtocellularlevelbeformstickymass
➢Dilutionofextractsmayoccurasbreakageofcellmay
resultinreleaseofallcellularcontent

38. Degreeofsizereduction
38
Dependsupon botanicalstructureofdrugs
➢Sliced(forsoftdrugslikegentian)
➢CoarsetoModeratelycoarse(forcascara,belladona)
➢Moderately fine(forhardandwoodydrugslike
ipecacuanha)
➢Coarsepowderforleafy structure

39. 2.Penetrationofsolventintothedrug
39
➢Adrugindrystateisporous-porescontainairthat
mustbedisplacedasthesolvententersintothepores
andpenetratesintothecells.
➢Whendrugisdried,micelle(celluloseincellwall)
losesitsfilmofwater
➢When the drug is moistened the micelle take up a
liquidfilmand tissueswell
➢Swelling continues until the pressure caused by liquid
layer is equal tothecohesiveforces betweenmicelle
➢Swellingmaycause
a.Distensionof cellwall
b.Burstingofthinwalledcell.

40. Solubilizationofconstituents(Dissolution)
40
➢When the solvent penetrates in the cells, dissolution
of the constituents takes place and is governed by
surface area,temperature,viscosity
➢Most important factors-increase the rate of
extraction-elevationoftemperature.

41. Escapeofsolutionfromthe cells(Diffusion)
41
Thedissolvedmaterialreachingthesurfaceoftheparticle
must pass through the boundary layer at the solid liquid
interface.
Therateofdiffusionwill dependonthe
➢suitableconcentrationgradientfromthecentreofthe
particle,outwardsandthroughtheboundary layer
➢Thicknessofboundarylayer
➢Diffusioncoefficientofthesoluteinthesolvent

42. Noyes’sWhitneyequation
Solution of the solid due to interfacial reaction to form a
thin film at the solid/liquid interface called a stagnant film
ordiffusionlayer which issaturatedwiththedrug(Cs)
42

43. 17
Noyes’sWhitneyequation
➢diffusioncontrolled
➢nochemicalreaction
“The rate of mass transfer of solute molecules or ions through a
staticdiffusionlayeris directlyproportionalto theareaavailablefor
molecular/ionic migration and concentration difference across the
boundary layer and is inversely proportional to the thickness of the
boundarylayer”
dC/dt=DA(Cs-Cb)/h
dC/dt=isthedissolutionrate
D=diffusioncoefficientofthesoluteinsolution
A=surfaceareaof theexposedsolid
h=thicknessofthediffusionlayer
Cs=Concentrationofsoluteparticleattheboundarylayer
Cb = concentrationof thesoluteinthe bulksolution

44. FactorinfluencingExtraction
44
I.Wheredrugimmersedinasolvent
Agitating themixtureoccasionally
➢By agitating the drug and solvent continuously
increases the concentration gradient by dispersion of
localconcentrationaswellasreducesthethicknessof
theboundarylayer
II. If thedrugispositionedsothatthesolventflowspast
theparticles
➢Theflowreplaces thesolutionbypuresolventcausingthe
increase intheconcentrationgradient

45. III.Elevatedtemperature’sadvantages
45
➢Solubilityof mostofthematerialis higherathigher
temperature
➢Viscosityofthesolventgetsreduceddecreasingboundary
layerthickness
➢Diffusion coefficient is proportional to the absolute
temperatureandinverselyproportionaltotheviscosity,so
raising the temperature influences the rate of diffusion
considerably

46. 20
Examples
➢Extraction offixed oilsfromseeds
➢Preparation ofalkaloid asstrychninefrom
nux-vomica,quininefromchinconabark
➢Isolationofenzymesasreninand hormonesas
insulinfrom animalsources
➢Extractionofmorphinefromopium
➢Reserpine fromRauwolfiaserpentina

47. Methodsofextraction
47
➢Maceration
➢Infusion
➢Percolation
➢Decoction
➢Digestion
➢Continueshotextraction
➢Supercriticalfluidextraction
➢Countercurrentextraction
➢Microwaveassistedextraction
➢Ultrasonication-AssistedExtraction

49. Typesofextraction
•Solidextraction:extractionofsolidfromsolidbyusingappropriatesolvent
•Solventextraction:processinwhichconstituentsthatareextractedbysolid
extractionprocessarepartitionedbetweentwoimmisciblesolvents.

50. StepsInvolvedintheExtractionofMedicinalPlants
Inordertoextractmedicinalingredientsfrom
plantmaterial,thefollowingsequentialstepsare
involved:
1.Plant tissue homogenization
2.Sizereduction
3.Extraction
4.Filtration
5.Concentration
6.Dryingandfurtherpurification

51. Planttissuehomogenization

53. MACERATION
53
Varioustypesofmacerationprocess are
➢SimpleMaceration:Aprocess fortincturesmadefrom
organizeddrug.e.g.roots,stems,leavesetc.
➢MacerationwithAdjustment:Aprocessfortinctures
madefromunorganizeddrugssuchas oleoresinsand
gumresins.
➢DoubleMacerationandTripleMacerationProcess:
forconcentratedpreparations

54. Maceration
Whole / coarsely powdered crude drug is placed in a stoppered
container with the solvent
Allow to stand @ room temperature for a period of at least 3 days with
frequent agitation until the soluble matter gets dissolved
The mixture then is strained, the marc (the damp solid material) is
pressed
The combined liquids are clarified by filtration or
decantation after standing

55. MACERATION
55

56. SIMPLEMACERATION
➢Drugisplacedinwidemouthedcontainer-stoppered
to prevent the evaporation of menstruum-mostly
concentratedalcohol
➢The drugisplacedwiththewholeofthemenstruum
inaclosedvesselfor7days
➢Duringthisperiodshakingis doneoccasionally
➢After7 daysliquidisstrainedand marcis pressed–
in filter press, hydraulic press or hand press, squeezed
inmuslinpieceetc..
➢Then filtered tomakeaclearliquid.
➢Thefinalvolumeis notadjusted.
➢E.g.tinctureoforange,tinctureoflemon
56

57. MACERATION WITHADJUSTMENT
➢Theunorganizeddrugis placedwith 4/5thof
menstruum in a closed vessel in a closed vessel for a
periodof2-7days
➢Shakingdoneoccasionally
➢After the stated period, the liquid is filtered and the
final volume is made up by passing the remaining
1/5thofthemenstruumthroughthefilter
➢Themarcisnotpressed
➢E.g. tinctureoftolu,compoundtinctureof
benzoin
57

58. Maceration fororganizedandunorganizeddrug
➢Organized:Puttotalmenstrum,marcispressed,vol
notadjusted
➢Unorganized: 4/5thofthe menstrum,marc-not
pressed,vol.adjusted
58

59. MULTIPLEMACERATION
MultipleMaceration:-Itisestablished
maximumextraction-multiplemaceration
59
thatthe
➢Totalquantityofmenstruumtobeusedisdividedin
suchawaythatsamequantityofmenstruumispresent
duringeachmacerationissameorucanusefresh
solvent
➢Sometimethissingleprocessofextractionisnot
sufficient,thendoubleortriplemacerationisalso
done
➢wholeprocessisrepeatedtomaketheextraction
processmoreeffective.

60. DOUBLE MACERATION
➢The drugismaceratedtwice withthemenstruum
whichisdividedintotwoequalvolume
Procedure
➢The wholeofthedrugis maceratedfor48hourswith
thequantityofmenstruumrequiredforfirstmaceration
➢Straintheliquidandpressthemarc.
60

61. DOUBLE MACERATION
61
➢Macerateagainfor24hourswith the remaining
menstruumrequired forsecondmaceration
➢Straintheliquidandpressthemarc
➢Mixtheliquidsobtainedfromtwomacerations, filter
andconcentrate
➢E.g. concentratedcompound infusionofChirata,
concentratedcompound infusionofGentian

62. TRIPLEMACERATION
➢Inthis process,thedrugis maceratedthricebyusing
menstruumwhichisdividedinto3parts in sucha
mannerthat samevolumeis usedforeach maceration.
➢Volumeofmenstruumrequiredbythefirstmaceration
➢Volumeofmenstruumrequiredbythesecond
maceration
62

63. TRIPLEMACERATION
➢The wholeofthe drugis maceratedfor1hrwithapart
ofmenstruumrequiredforfirstmacerationandstrained.
➢Macerateagainfor1 hrwithapart ofmenstruum
required for2ndmacerationand strained.
➢Macerate againfor1 hrwithapart ofmenstruum
required for3rdmacerationand strained.
➢Pressmarclightlythencombinetheliquidobtained
from 2nd and3rd macerationandevaporateit toa
specificextent
63

64. TRIPLE MACERATION
64
➢Addalcohol 90%equalto1/4thofthevolume ofthe
finishedproduct
➢Adjustvolumewithwater.
➢Allowtostandfor14daysandfilter
➢E.g. concentrated infusion of Quassia, liquid extract
ofSenna

65. Infusion
➢adrink,remedy,orextract
soakingleavesorherbsinliquid
preparedby
➢Infusionistheprocessofextractingchemical
compoundsorflavoursfromplantmaterialina
solventsuchaswater,oiloralcohol,byallowing
thematerialtoremainsuspendedinthesolvent
overtime(aprocessoftencalledsteeping)
➢Resultantliquid-infusion
65

66. Infusion

67. 23
Infusion
➢Containsreadily-solubleconstituentsofcrude
drugs.
➢Formerly,freshinfusionswere used
➢Now,fresh infusionsare usuallyprepared by
diluting one volume of a concentrated infusion to ten
volumes with water.
➢Concentratedinfusions -modifiedpercolationor
macerationprocess.
➢Fresh infusions-fungus and bacterial growth-
dispense them within twelve hours of their
preparation
➢Usedfor softdrugs

68. ➢It involves pouring water over drugs and allowing
ittokeepin contactwithwaterforthestatedperiod,
usually15 minutes, withoccasionalstirringand
finallyfiltering offtheliquid
➢Marcisnotpressed
➢Boilingwatercanbeusedas solvent
➢Afterthespecifiedtime theliquidis filteredand
dispenseasdrug
➢Short timeissufficientforextractiondue toreadily
solubleconstituentofcrudedrug
24
Procedureused

69. 40
PERCOLATION
➢Itiscontinuousdownwarddisplacementofthesolvent
throughthebedofcrudedrugmaterial togetextract.
1.Simplepercolationorpercolationprocessfor
tinctures.
2.Percolationprocessesforconcentratedpreparations
suchas:
i.Reservepercolationprocess
ii.Modifiedpercolationprocess
3.ContinuoushotpercolationorSoxhelation

70. Percolation
•
•
•
•
Usedmostfrequentlytoextractactiveingredientsinthe
preparationoffluidextracts
Thesolidingredientsaremoistenedwithanappropriateamount
ofthespecifiedmenstruum
Allowedtostandforapproximately4hoursinawellclosed
container,Afterstandtime,themassispacked&thetopofthe
percolatorisclosed
Themixtureisallowedtomacerateintheclosed
percolatorfor24h

71. •
Additionalmenstruumisaddedasrequired,untilthe
percolatemeasuresabo,utthree-quartersoftherequired
volumeofthefinishedproduct
•
Themarcisthenpressedandtheexpressedliquidis
added to thepercolate
•Sufficientmenstruumisaddedtoproducetherequired
volume
•Themixedliquidisclarifiedbyfiltrationorbystanding
followed bydecanting

72. PERCOLATION –APPARATUS
72
➢Apercolator(anarrow,cone-shapedvesselopenatboth
ends)isgenerallyused.
•Conicalpercolator
•Cylindricalpercolator
•Steam jacketedpercolator

73. Conical
73
Cylindrical
SimplePercolator

74. TypesofPercolation
1.SimplePercolation
i)TinctureofBelladonna
ii)Compoundtinctureofcardamom
2.ModifiedPercolation
➢Repeatedmacerationismoreeffectivethansimple.
➢Multiple maceration –Solvent divided into equal
multipletimeconsideringthe solventretainedbyplant
tissue.
➢Used toprepareconcentratedpreparation.
74

75. Stepsinpercolation
75
1.Sizereduction:Thedrug to beextractedissubjected
to suitable degree of size reduction, usually from
coarsepowder tofinepowder.
2.Imbibition: During imbibition, the powdered drug is
moistened withasuitableamountofmenstruumand
allowed to stand for four hours in a well closed
container.
➢It isdoneinordertoallowswellingof thetissues
beforepackingintothepercolator.
➢Drypowderifpackedintopercolatormaycause
blockageof thepercolator.

76. ➢Itallowsentrappedairtoescape,drypowderdrug
would have air entrapped within them, this may
resist the flow of menstrumm and will disturb the
packingofthe powdered drug.
➢Priortopackingoftheimbibeddruginto
percolator,uniformityofparticlesizeisensured
bypassingthemoistenedmassthroughasieveof
coarseaperture.
76

77. 3.Packing:Afterimbibitionthemoisteneddrugisevenly
packedintothepercolator.
77
➢Glasswoolmoistenedwithsolventiskeptatthebottomtoavoid
blockageofoutletortap.
➢Theimbibeddrugispackedinthepercolatorupto2/3rdor3/4th
ofthevolumeofpercolator.
➢Filterpaperisplacedabovethislayerandabovethisalayerof
sandisplacedinordertopreventdisturbanceoftoplayerwhenthe
menstrummisaddedintothepercolator.
➢Sufficientquantityofmenstruumneedstobeaddedtosaturate
thematerial.
➢Whentheliquidstartscomingoutofthepercolatoroutletis
closedandaddmenstrummformingalayerofsolventabovethe
imbibedmass.

78. 4.Maceration:The percolator isallowedtostandfor
24 hourstomaceratethedrug.Duringthistime,
menstruumgets saturatedwith drug.
78
Itconsistsofthedownward
thesaturatedsolutionformedin
5.Percolation:
displacementof
macerationandextractionoftheremainingactive
constituentspresentinthedrugbytheslowpassageof
themenstruumthroughthecolumnofthedrug.

79. SIMPLEPERCOLATION
79
➢Aftercollecting3/4thoftherequiredvolume ofthe
finished product or when the drug is completely
exhausted,themarcispressed.
➢Mix theexpressedliquidwith percolate..
➢Addsufficientquantityofmenstruumtoproducethe
required volumeandthen filter.
➢E.g.tincture of belladona
➢compoundtinctureofcardamom
➢strongtinctureof ginger.

80. PERCOLATION PROCESS FOR
CONCENTRATED PREPARATIONS
80
➢Usedtoprepareliquidextractsandsolidextracts.
Typesofprocessesare:
➢Reservepercolationprocess.
➢Modifiedpercolationprocess

81. ReservedPercolationProcess
81
➢Inthisprocess,apartofpercolate,usually3/4thofthevolumeofthe
finishedpreparation,isreserved(firstpercolate)containinghighsolute
concentration.
➢Percolationprocessiscontinuedtillthedrugiscompletelyexhausted.
➢Thepercolatethusreceivescontainstracesofactiveconstituentsofthe
drug.
➢Evaporationordistillationisdonetorecoverthecostlymenstruum.
➢Hence,themajorportionoftheactiveconstituentsofthedrug are
saved fromdetorioration.
➢Theremainingsoftextractis thenaddedtoreservepercolate.
➢Volumemake upisdoneusing menstruum.

82. MODIFIEDPERCOLATION PROCESS
➢Innormalpercolationprocess,thedrug/percolate(d/p)
ratioisabout1:4,thed/pratioisreducedto1:3by
modifyingthepercolationprocessandhencethereisalot
ofsavinginheat,timeandmenstruum.
➢Percolationisthedisplacementprocess.
82
➢The
formed
strongsolutionofactiveconstituents
duringmacerationisdisplacedby
ofdrug
thefresh
menstruumwhenpercolationprocess isstarted.
➢Menstruumremainingincontactwiththedrugdissolves
more matterthantheflowing menstruum.

83. 52
MODIFIEDPERCOLATION PROCESS
➢Simplepercolationprocess-moremenstruumisrequired to
exhaustthedrug.
➢In simplepercolation process
➢DrugImbititionMaceration percolationand
collect the percolate, i.e. ¾ of the volume of the finished
product.
➢In modifiedpercolationprocess:
Drug-imbibition-maceration-percolationandcollect
1000mlofpercolate(24hr)
Secondtime:1000mlof percolate (12hr)
Thirdtime1000ml ofpercolate (12hr)
Drug:percolate1000gm:3000mld/p=1:3

84. MODIFIEDPERCOLATION PROCESS
➢After exhaustion of the drug, the percolate is
evaporatedandthenmixedwiththemainpercolate.
➢The final volume is made by adding more of
menstruum.
84

85. Continuoushotpercolationprocessorsoxhlet
extraction orsoxhleation
85
➢Whenactiveconstituentsofthedrugarenotfreelysoluble
inthesolventordifficulttobedisplacedfromthecellsofthe
drug,thenitbecomesnecessarytoextractthecrudedrugby
actionofhotmenstruumforaconsiderablelengthoftime.
➢Thefixedoilsfromseedsandalkaloidsfromthedrugare
extractedbycontinuoushotpercolationprocessusing
benzene,chloroform,petroleum,etheretc.

86. SoxhletExtraction
(HotContinuousExtraction)

88. Sonication
(UltrasoundExtraction)
•
•
Involvestheuseofultrasoundwithfrequenciesrangingfrom
20kHzto2000 kHz
Increasesthe permeabilityofcellwalls& producescavitation
Disadvantage
Deleteriouseffectofultrasoundenergy
medicinalplantsthroughformationof
(>20kHz)ontheactiveconstituentsof
free
radicalsandconsequentlyundesirablechanges
inthe drug molecules

89. 89

90. Soxhletapparatus
90
1.Flaskcontainingtheboilingwater
2.SoxhletExtractor: in which thedrugto be
extractedis packed.
➢It has a side tube which carries the vapors of the
solvent from the flask to the condenser and a siphon
tubewhichsiphonsoverthe extractfromsoxhlet
extractortothe flask.
3.Acondenserinwhichthevaporsofthesolventare
condensedagainintosolvent.

91. Soxhlation
91
PROCEDURE
➢Thedrugispackedinapapercylindermadefromafilter
paperanditisplacedinthebodyofsoxhletextractor.
➢Thesolventisplacedintheflask.
➢Theapparatusisthenfittedasshownisfigure.
➢Whensolventisboiledonheatingflask,itgetsconverted
intovapours.
➢Thesevapoursenterintothecondenserthroughtheside
tubeandgetcondensedintohotliquidwhichfallson
columnofthedrug.
➢Whentheextractorgetsfilledwiththesolvent,thelevel
ofsiphontubealsoraisesuptoitstop.

92. Soxhlation
92
➢Thesolventcontainingactiveconstituentsinthesiphon
tubesiphonoverandrunintotheflask,thusemptyingthe
bodyofextractor.
➢Thisalterationoffillingandemptyingthebodyof
extractorgoesoncontinuouslyuntilthedrugisexhausted
(normally15times).
➢Thesolubleactiveconstituentofthedrugremaininthe
flaskwheresolventisrepeatedlyvolatilized.

93. 25
DECOCTION
➢Extractionfrom hard andwoodycrudedrugs
➢water soluble and heat stable constituents are
extractedout
Procedure
➢Water is used as a solvent and the crude drug
which istobeextracted iscutintosmallpiecesand
boiled withwaterforthestatedtime, usually10to
15minutes ina vesselofenameledironor
earthenware-counting from when the liquid starts to
boilwithoccasionalstirring

94. Decoction
➢Suitableforextractingwater-soluble,heat-stableconstituents
➢Typicallyused inpreparationofAyurvedicextracts

95. 26
➢Toobtainhighlyconcentrateddecoction,boilingis
continueduntiltheliquidreducedtoacertainvolume
➢Allowto cooltoabout 40ºC,pressthemarcandmix
theresultingliquidtothedecoction
➢At the end of decoction time, decoction is strained
throughfinemuslin
➢Then, sufficient water is passed through the strainer to
producea definitevolume
➢Example: Cinchonabarkor wood (contains quinine)

96. INFUSION DECOCTION
➢Used forsoft drugseg,sennaleaves➢Usedforharddrugs (Cinchonabark)
➢Cold orboilingwaterused ➢Boilingwater
➢Thermolabileconstituents ➢Thermostableconstituents
➢Liquidisstrained&volumenot
adjustedbywashingthemarc
➢Liquidis strained&volumeadjusted
by washingthemarc
➢Timecalculatedassoonaswateris
added
➢TimeCalculatedassoonaswater
beginstoboil
96

97. DIGESTION
97
➢Digestionis the processinwhich heat aswellas
pressureis usedforextraction
➢The equipmentislikea pressurecookeror
autoclaveand iscalled digester
➢Extraction of non-thermolabilematerialsis
more efficientin it because ofhighpenetration
power of solvent and solubilisation rate of soluble
mattersofthecrude drug due tohigh pressureand
temperature respectively

98. Digestion
•Aformofmacerationinwhichgentleheatisused
duringtheprocess ofextraction
•Usedwhenmoderatelyelevatedtemperatureisnot
objectionable
•Thesolventefficiencyofthemenstruumisthereby
increased
Microwavedigestionsystem

99. SUPER-CRITICALFLUIDEXTRACTION
99

100. Supercritical????
10
0
Critical point: T & P at
whichliquid&gasphase
doesn’tdistinguish.
Foreg:CO
2–31°Cand74
bar
Supercritical:T&Pabove
criticalpoint.
Insupercriticalregion,fluid
exhibitsparticularproperties
•Liquidlikedensity
•Gaslikeviscocity
•Diffusivity intermediate
b/wgasandliquid

101. PROPERTIESOFSCF
10
1
➢PhysicalandthermalpropertiesofSCFsarein
betweenpureliquidandgas,hencecanalsobeknownas
‘Compressibleliquids’or‘densegases’
Changedproperties
➢Liquid like densities (100-1000 times greater than
gases)
➢Diffusivitieshigherthanliquids
➢Goodsolvatingpower
➢Reductioninsurfacetension
➢Low viscosity(10-100times less thanliquid)
➢Gas likecompressibilityproperties
Thereforethey posseshighpenetratingpower

102. 10
2

103. 10
3

104. SUPERCRITICALFLUIDEXTRACTION(SFE)
10
4
➢Supercriticalfluidextractionistheprocessofseparating
onecomponentfromanother(thematrix)using
supercriticalfluidsastheextractingsolvent

105. Figure:Flowdiagrammeof SCFE
10
5

106. COMPONENTS OFSFE
10
6
1.Fluidreservoir(gas cylinderincaseofCO
2)
2.Pump–Reciprocatingpump–Syringepump
(pulse-freeflow atlargerange of flowrates)
3.Extractioncell/column(stationaryphase)–Usually
stainlesssteelChamberorvesselincompartment–
Capableofwithstandinghighpressure(300-600
atm)[forsolids] –Opentubularcapillary columnsor
packedcolumns [liquids])

107. COMPONENTS
4.Restrictor–Maintainingpressurechangeinsidethe
extractionvessel
5.Collector (trapping system) : Collects the
componentswhichareextracted
6.Detectors(flameionizationdetectorofgas
chromatography)
10
7

108. SUPERCRITICALFLUIDEXTRACTION (SFE)
Introductionoffeedintoextractor(solidfeed)orextractorin
modifiedcolumneither co-currentlyorcounter-currently
Formationofmobilephase:mixingofsoluteswithsupercritical
fluid.
Exposureofmobilephasetopressures(50-500atm)and
temperatures(ambientto300°C)nearorabovethecriticalpoint
forenhancingthemobilephasesolvatingpower
Isolationofdissolvedsolutebyprecipitation
Eg.CO
2invapourformiscompressedintoaliquidbefore
becomingsupercriticalandthenextractiontakesplace.
10
8

109. 10
9

110. SampleMatrixParametersthatinfluence SFE:
➢Particlesizeandshape
➢Surfaceareaandporosity
➢Moisturecontent
➢Changesinmorphology
➢Samplesize
➢Extractableslevel
Theparameters effectonsolubility:
➢The vapourpressure of thecomponent
➢Interactionwiththesupercriticalfluid
➢Temperature,pressure,densityand additives
11
0

111. ADVANTAGES
11
1
➢Elimination oforganicsolventsi.e.reducestherisk
ofstorage.
➢Rapid (due to fast back-diffusion of analytes in the
SCF reduces the extraction time since the complete
extractionstep isperformedinabout20min)
➢Suitable for extraction and purification of compounds
havinglow volatilitypresentinsolidorliquid
➢Susceptibletothermaldegradation (lowoperating
conditions,usedforthermolabilesubstances)

112. ADVANTAGESCONTD..
➢Complete separationofsolvent fromextract
➢Continuousprocess
➢Lowhandlingcost
➢Solventrecoveryiseasy
➢Versatileandefficient(use ofco-solventsandco-
solutes)
11
2

113. LIMITATIONS
11
3
➢Prolongedtime(penetrationofSCFintothe
interiorofasolidisrapid,butsolutediffusion
fromthesolidintotheSCF).
➢Modelingisinaccurate
➢Expensive
➢Consistency&reproducibilitymayvaryin
continuousproduction

114. PRECAUTIONS
11
4
➢Adequatecontacttime(forpenetrationofsolvent
intosolidparticlesanddiffusionofsolutefrominside
thesolidparticlestosolvent)
➢Equilibriumshouldbeachieved(i.e.properflowof
solventsuchthatconcentrationofdissolvedsolutesin
thesolventphasewillbebelowthesolubilityofsolute
insolvent)

115. Extraction Process
THE END

116. Any Questions

117. References
11
7
➢TutorialPharmacybycooper andguns.
➢Pharmaceutics Iby Mehta
➢Google.
➢https://www.youtube.com/watch?v=XBZkVEWxlnU
➢https://youtu.be/mLq35x0g46g
➢https://youtu.be/LQfVJ0MvqEo

118. Study Questions
Define the following terms:
✓[Pharmacognosy, phytochemical, extraction,
Infusion, Decoction, Digestion, Maceration,
Percolation, nutraceutical, toxicity, diversity,
penetration, solubilization, homonization,
Menstrum, Marc, Extractives, Tinctures,
Soxhlation, decoction, etc]

119. Study Questions
Respond to the following questions:
•Give an outlined preview of extraction process
• Give an outlined preview of phytochemicals
•What factorials considerations for extractive process?
•What are Ideal properties of extractive solvent?
•State the Advantages and disadvantages of extractive solvents.
•What is Infusion process as part of extraction?
•What is Decoction process as part of extraction?
•What is Digestion process as part of extraction?
•What is Maceration process as part of extraction?
•What is Percolation process as part of extraction?
•What is Continues hot extraction process as part of extraction?
•What is Supercritical fluid extraction process as part of extraction?
•What is Counter current extraction process as part of extraction?
•What is Microwave assisted extraction process as part of extraction?
•What is Ultrasonication - Assisted Extraction process as part of extraction?
•What is the primary goal of extraction processes in phytochemistry?
•Define maceration as a method of extraction.
•What are the main differences between maceration and percolation?
•How does the choice of solvent affect the extraction process?
•What are the advantages of using ethanol as an extraction solvent?
•What is the role of temperature in the extraction process?
•How does solvent polarity influence the extraction of phytochemicals?
•What are the main steps involved in a cold extraction process?
•What are the benefits of using supercritical CO2 in extraction?
•How is the efficiency of an extraction process measured?
•What are the safety considerations when performing extractions?

120. Study Questions
Respond to the following questions:
•What is the importance of pH in the extraction process?
•What is the significance of the partition coefficient in extraction processes?
•What is the primary goal of extraction processes in phytochemistry?
•Define maceration as a method of extraction.
•What are the main differences between maceration and percolation?
•How does the choice of solvent affect the extraction process?
•What are the advantages of using ethanol as an extraction solvent?
•What is the role of temperature in the extraction process?
•How does solvent polarity influence the extraction of phytochemicals?
•What are the main steps involved in a cold extraction process?
•What are the benefits of using supercritical CO2 in extraction?
•How is the efficiency of an extraction process measured?
•What are the safety considerations when performing extractions?
•What is the importance of pH in the extraction process?
•What is the significance of the partition coefficient in extraction processes?
•What is the primary goal of extraction processes in phytochemistry?
•What is the principle behind the extraction of phytochemicals from plant material?
•Define the term 'solubility' in the context of extraction processes.
•How does the diffusion rate affect the extraction process?
•What role does the surface area of plant material play in extraction efficiency?
•What is the importance of solvent selectivity in extraction?
•How does particle size of plant material influence the extraction process?
•What is meant by 'equilibrium' in extraction processes?
•What factors influence the rate of extraction?
•How does temperature impact the solubility of phytochemicals?
•What is meant by 'dynamic equilibrium' in the context of extraction?

121. Study Questions
•Respond to the following questions:
•What is the role of diffusion coefficient in the extraction process?
•How does the nature of the plant matrix affect the extraction process?
•What is the principle behind Soxhlet extraction?
•How does percolation differ from maceration?
•What is decoction and how is it performed?
•How is microwave-assisted extraction carried out?
•What are the advantages of ultrasound-assisted extraction?
•What is the principle behind supercritical fluid extraction?
•How does hydrodistillation work for extracting essential oils?
•What is the principle of liquid-liquid extraction?
•How is solid-phase extraction performed?
•What are the advantages of using enzyme-assisted extraction?
•What is the principle behind accelerated solvent extraction?
•How is aqueous extraction performed and in what scenarios is it used?
•What distinguishes maceration from other extraction methods?
•How does Soxhlet extraction improve efficiency over simple maceration?
•What is the principle of reflux extraction and its common uses?
•How does ultrasound-assisted extraction enhance phytochemical yield?
•What are the key steps involved in microwave-assisted extraction?
•How does steam distillation differ from hydrodistillation?
•What are the benefits of using solid-phase extraction?
•How is accelerated solvent extraction performed?
•What is enzyme-assisted extraction and when is it used?
•How does cold pressing differ from other extraction methods?
•What is the principle of Soxhlet extraction, and why is it effective for certain types of phytochemicals?
•What are the advantages of using supercritical CO2 extraction over traditional solvent extraction?
•How does the method of infusion differ from decoction?

122. Study Questions
Group work discussional questions:
•Describe the process of Soxhlet extraction.
•Explain the principle behind solid-liquid extraction.
•Describe the method of decoction and its typical applications.
•Define the term 'menstruum' in the context of extraction.
•Explain the process of supercritical fluid extraction.
•Describe the use of ultrasound in enhancing extraction efficiency.
•Explain the term 'extraction yield' and how it is calculated.
•Explain the concept of partition coefficient in extraction.
•Describe the term 'mass transfer' in the context of extraction processes.
•Explain the relationship between solvent concentration and extraction
yield.

123. Study Questions
Group work discussional questions:
•Describe the role of agitation in enhancing extraction efficiency.
•Explain the concept of 'extraction kinetics.'
•Explain the principle of solvent polarity and its relevance in
extraction.
•Describe the term 'desorption' in the context of extraction.
•Explain the importance of solvent-to-sample ratio in extraction
efficiency.
•Explain the process of infusion and its typical applications.
•Describe the principle and procedure of reflux extraction.
•Explain the process of cold pressing and its applications.
•Describe the steps involved in steam distillation.
•Explain the process of solvent extraction.
•Describe the method of countercurrent extraction.

124. Study Questions
Group work discussional questions:
•Explain the process of pressurized liquid extraction.
•Describe the process and application of percolation in extraction.
•Explain the process of supercritical fluid extraction using CO2.
•Describe the method of liquid-liquid extraction and its uses.
•Explain the principle and application of pressurized liquid extraction.
•Describe the method of countercurrent extraction.
•Explain how aqueous extraction is used for water-soluble compounds.
•Describe the principle and application of hydrodistillation for essential
oils.
•Give detailed explanation the Factorial considerations of extraction
process
•State the advantages and disadvantages of various methods applicable
in the process of extraction
•Give detailed mechanisms of extraction process with examples

125. Study Questions
Group work discussional questions:
•Explain the Parameter that are considered for extraction methods
•Give detailed description with examples the extractive solvent drug
penetration process
•Describe the Steps that are considered during the extraction process
•Describe the following methods of extraction in terms of processes followed
and the ultimate results:
✓Infusion
✓Decoction
✓Digestion
✓Maceration
✓Percolation
✓Continues hot extraction
✓Supercritical fluid extraction
✓Counter current extraction
✓Microwave assisted extraction
✓Ultrasonication - Assisted Extraction