Percolation process.

Introduction and Process

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: Comminution of the drug. Imbibation. 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 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.