The document describes the percolation process, which is a method of extracting active constituents from drugs using a solvent. It involves comminuting the drug into a fine powder, imbibing it with solvent, packing it into a percolator, macerating it for 24 hours, then slowly percolating more solvent through it while collecting the extract. The key steps are size reduction of the drug, moistening it with solvent, packing it uniformly in a conical percolator, macerating it overnight, then slowly draining more solvent through it over multiple days to extract the active compounds.

1. Percolation Process
 Presentation By:- Sayed Ali Akbar Bukhari

2. Introduction:-
 Percolation is also known as another method of
extraction of active constituents from the drugs. It is the
process of a liquid slowly passing through a filter.
 Percolation is derived from a latin word Percolare.
 “Per” which means “through” and “Colare” which means
to “strain”.

3. Process:-
 In this process the suitably comminuted drug is moistened
with a sufficient quantity of menstrum( the solvent used for
extraction), which is then packed in a percolator. The drug
is allowed to remain in contact with the menstrum for 24
hours, then more of menstrum is added and the
percolation is started.

4.  The entire Percolation process is explained by
dividing it into following stages:
1. Comminution of the drug.
2. Imbibation.
3. Packing.
4. Maceration.
5. Percolation.

5. 1. 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 movment of menstrum
 For uniform packing

6. 2. Imbibation:-
 During Imbibation the powdered drug is moistened
with a suitable amount of menstrum and allowed to
stand for 4 hours in a well closed container. During
this period the drug swells up by absorbing the
menstrum. This moistening of drug is necessary for
following objectives:
 To avoid choking( difficulty in movement ).
 To remove air.
 To avoid washing out of fine particles.

7. 3. Packing:-
 After Imbibation the moistened drug is evenly
packed into a percolator. A percolator is a conical
vessel having a lid at the top and is provided with a
false bottom on which filter paper or cotton wool is
placed to support the drug and help in the escape
of percolate.

8.  For packing a piece of cotton wool
or a filter paper is placed on the false
bottom of percolator.
 Then the moistened drug is
introduced into the percolator.
 Again a filter paper or cotton wool is
placed over the top of drug on
which small quantity of washed sand
is placed to prevent the distrubance
of packed material.

9. 4. Maceration:-
 After packing sufficient menstrum is added
and the top of the percolator is covered
with lid.
 When the liquid begins to drip from the
bottom of the percolator the tap fitted at its
bottom is closed.
 Then the percolator is set aside for 24
hours.

10. 5. Percolation:-
 After 24 hours the lower orifrice 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 orifrice so
that the marc does not become dry.
 Then marc is pressed to extract which
is combined with previois liquid.
 Then it is allowed to stand and then it
is filtered.