This document discusses different types of solid-liquid and liquid-liquid extraction processes. Solid-liquid extraction, also called leaching, involves removing soluble components from an insolute matrix using a solvent. It occurs through diffusion of the solvent into the solid and diffusion of the dissolved components out of the solid into the solution. Common solid-liquid extraction techniques include maceration, percolation, digestion, and countercurrent extraction using equipment like diffusion batteries, rotocel extractors, and screw extractors. Liquid-liquid extraction relies on the partition of compounds between two immiscible liquid phases. Large-scale equipment used in extraction includes mixers, towers, spray towers, and agitated columns.

1. Extraction
Solid – Liquid
&
Liquid - Liquid

2. • Removal of soluble fraction in the form of solution from an
insoluble matrix with which the soluble fraction is associated
with the help of suitable solvent.

3. Mechanism of solid – liquid extraction
• Mechanism of solid – liquid extraction also known as
“leaching”, involve simple physical solution or dissolution
made by chemical reaction.
• diffusion of solvent – dissolution of chemical constituents –
diffusion of solution.
• Extraction enhanced by increased surface area and decreased
radial distance by decreased particle size .

5. Different types of Extractions

6. INFUSION

7. DECOCTION

8. Digestion
is maceration by heating the drug-menstrum
mixture in a closed vessel.
Eg:Shark liver oil with Malt extract IP

9. • SIMPLE MACERATION
• MACERATION WITH ADJUSTMENT
• MULTIPLE MACERATION
MACERATION:

10. SIMPLE MACERATION:
Eg: Orange tincture IP.

11. • Strained liquid and Expressed liquid are mixed
after clarification of expressed liquid.
• Final volume is not adjusted to initial volume
because dilution occurs.

12. MACERATION WITH ADJUSTMENT
Eg: Benzoin tincture BPC.

13. MULTIPLE MACERATION
Eg: Bael liquid Extract IP

14. PERCOLATION
Eg: Belladona Tincture IP

15. PERCOLATION

16. Percolation with interruption
Involves extraction by alternative process of
maceration and percolation for 2 to 3 times.

17. Percolation with interruption

18. Reserved Percolation
Eg: Quillaia Liquid extract BPC

19. Continuous Hot Percolation Soxhlet apparatus

20. Galenical preparations
• Aromatic waters.
• Tinctures.
• Elixir.
• Spirits.
• Extracts : liquid, soft and dry.

21. Aromatic waters
• Camphor water IP
• Chloroform water IP

22. Tinctures
• Compound Benzoin tincture IP
• Compound Cardamom tincture IP

23. Elixir
• Cascara elixir BPC.
•
•
•

24. Extracts
• Liquid extract
– Cinchona Liquid extract IP.
– Senna liquid extract BPC.
– Liquorice liquid extract IP.
•

25. Choice of extraction process
• Depends on physico chemical char. Of raw
material and economic consideration.
• Maceration: - is suitable for unorganised drug, and
whose permeability is low.
• Percolation:- rapid and complete extraction, skill care
and frequent attention is needed

26. Large scale equipment
• Large circular and rectangular towers with
false bottom
• Mechanism of extraction
• In solid - liquid E: “Leaching”
• In Liquid – Liquid E: “Partition”

27. Solid - Liquid Extraction
• Carried in different methods
• A. Simple single contact.
• B. Simple multiple contact.
– Fresh solvent is in contact with CD, after first
extraction, repeated extracts are dilute, recovery
of solute is improved.
• C. Continuous Counter current contact
• Are carried out in different methods

28. • Discontinuous absolute extraction, in which the
extraction solvent and drug are moved against each
other.
• Continuous relative counter current extraction,
solvent is in motion and other phase i.e solid remains
stationary.
• Continuous Absolute counter current extraction
contact involves continual movement of both solvent
and CD.

30. Solid - Liquid Extraction Equipment
• Simple single stage contact
– Mixers
– Vortical extractor
– Ultrasound extractor – Ultra sonic transmitters for accelerating
extraction about 20,000 Hz.
– Electrical discharge extractor.
• Counter current contact
– Diffusion battery
– Rotocel extractor
– Basket extractor
• Continuous absolute extractor
– Screw extractor
– Hilderbrandt Extractor
– Pulsation column extractor

31. Diffusion Battery

32. Rotocel or Carousel extractor

34. Screw Extractor
CD and solvent are in opposite direction, sections are heated or cooled. Factors
affecting working of extractor is - Angle of inclination of cylinder, temp of solvent
speed of rotation feed charge and rise in pressure inside the cylinder.

35. Silver Continuous diffusion battery
• Less labour cost and produce high conc.s
• 20-24 units in two tiers, one above the other.
• Closed trough, helical screw, at the end
consists of wheel consists inclined perforated
buckets- pick CD and drain the liquid, dischare

38. Hilderbrandt Extractor

39. Basket extractor :

40. Extraction of Fine solids

47. Spray tower:

48. Perforated plate extraction towers:

50. Baffle plate column extractor

53. Agitated Column:
• Mechanical agitations in: Schibel,
Mixco, Reciprocating column &
rotating disc contractor
Reference:
Introduction to Pharmaceutical
Engineering by Anant Paradkar.
Pg.No: 190

54. Agitated tower extractor
References: 1. Unit operations of chemical engineering by Warren L. McCabe, Julian C.Smith.
2. Introduction to Pharmaceutical Engineering by Anant Paradkar Pg.No: 190