percolation extraction process

1. Percolation
By :GHULAM UMAR Maitlo
maitloumar8@gmail.com

2. Introduction
 Percolation is the process of a liquid slowly
passing through a filter.
 Percolation comes from the Latin word
percolare, “Per” which means “through”
and “Colare” means to “strain”
 Percolation happens when liquid is strained
through a filter, like when someone makes
coffee.

3. COMMON EXAMPLES
Coffee: In coffee percolation soluble
compounds leaves the coffee and join the
water. Insoluble components remain within
the coffee filter.
Coffee percolation

4. PROCESS
The process of percolation includes five
steps.
 Comminution of drug
 Imbibition of drug
 Packing
 Maceration
 Percolation

5. COMMINUTION
It is the size reduction of drug usually from
coarse powder to fine powder so that....
 To increase surface area
 To ensure complete removal of drug
 To slow down the movement of menstrum
 For uniform packing

6. IMBIBITION
Imbibition Swelling of drug by absorbing
menstrum. It is allowed to stand for 4 hours in
a closed container. It is done to achieve
following objectives;
 To avoid choking(difficulty in movement)
 To remove air
 To avoid washing out of fine particles

7. PACKING
PACKING
 After imbibition drug is evenly packed into the
percolator.
 The a filter paper is placed on the bottom to support
the column of drug.
 Then the moistened drug is placed on the filter paper.
 Over the moistened drug another filter paper is
placed having weight on it.
 Then menstrum is added. Close the lid if menstrum is
volatile.

8. MACERATION
MACERATION
 After packing sufficient menstrum is added and
covered with lid.
 When liquid begins to drop the lower orifice is
closed.
 Then percolator is set aside 24 hours.

9. Percolator

10. PERCOLATION
PERCOLATION
 After 24 hours lower orifice is opened and menstrum is
collected with a controlled speed until ¾ of menstrum is
collected.
 Then more menstrum is added and collected from the
lower orifice so that marc does not become dry.
 Then marc is pressed to get extract which is combined
with previous liquid.
 Then it is allowed to stand and then it is filtered.

11. MODIFIED PERCOLATION
MODIFIED PERCOLATION
 Reserved percolation
 Continuous hot percolation
 Continuous cold percolation Reserved
Reserved percolation:
This type of percolation is done to get concentrated
preparation.
Process:
 In this method the first portion(about ¾ portion) of
percolate contains maximum amount of active
constituent(70 to 80%) is reserved as such..

12.  The last portion of percolate(about ¼ ) is
collected separately and menstrum is
evaporated to get syrupy consistency and
mixed with reserved percolate. Final volume is
adjusted by adding more menstrum. Usually
alcohol is use as menstrum for reserved
percolation.
 Example: Liquorice liquid extract

13. CONTINUOUS HOT PERCOLATION
 This process is done for those drugs in which percolation of
menstrum into cellular tissues is very low.
Apparatus:
 The apparatus use for this process is called as KUMAGAWA
EXTRACTOR.
Process:
 The menstrum present in the flask is heated and vapours are
taken to a condenser where the condensed liquid is return to
the drug to continue extraction.
ADVANTAGES:
 Smaller volume of menstrum can be use again and again.

14. kumagawa extractor

15. Continuous cold percolation
The apparatus is called as
Soxhelt extractor

16. DISADVANTAGES OF
CONTINUOUS PERCOLATIONS
 This type of percolation is not suitable for those
drugs which contains heat sensitive active
constituents.