1. Problems associated with the manufacturing of tablets
Presented by
Radwa Ahmed Taha
B. Pharm Sciences, Mansoura University
Under the supervision of
Prof. Dr/ Thanaa M. Borg
Professor of pharmaceutics
Head of pharmaceutics department
Faculty of Pharmacy
Mansoura University

2. The problems associated with the manufacturing of tablets
In the normal process of developing formulations, and the routine manufacture of tablets, various problems occurs. Sometimes, the source of the problem is the formulation, the compression equipment, or a combination of the two.

3. 1-Capping and lamination
Capping : the partial or complete separation of the top or bottom crowns of the tablet from the main body of the tablet.
Lamination :the separation of a tablet into two or more distinct layers.
Solution :
1- precompression
2-slowing the tablet rate
3-reducing the final compression pressure.
4-use of flat punches
5-provide a certain percentage of moisture (addition of hygroscopic materials for moisture-critical granules)

4. 2-Picking and sticking
Picking : the surface material from a tablet that is sticking to and being removed from the tablet's surface by a punch.
Sticking: material adhering to the die wall.
Solutions:
1- Lettering should be designed as large as possible
2-Plating of the punch faces with chromium
3-Addition of colloidal silica to the formula to act as a polishing agent and makes the punch face smooth so that material does not cling to them
4-Low-melting point substances tend to sticking. Addition of high-melting point substances and ,increase the size of tablet and refrigeration of the granules and press can solve this problem.

5. 3-Mottling
Mottling : an unequal distribution of color on a tablet, with light or dark areas standing out in an otherwise uniform surface.
Solutions :
1-Use of colorants
2-Change the solvent system, change the binder system, reduce the drying temperature, or grind to a smaller particle size.

6. 4-Weight variation
The weight of a tablet being compressed is determined by the amount of granulation in the die prior to compression. Therefore, anything that can alter the die-filling process can alter tablet weight and weight variation.

7. 5-Granule size and size distribution before compression
although the apparent volume in the die is essentially the same, different proportions of large and small particles may change the weight of fill in each die.

8. 6-Poor flow
The die-fill process is based on a continuous and uniform flow of granulation from the hopper through the feed frame.
Dies are not filled properly when granulation does not flow readily or when machine speed is in excess of the granulation's flow capabilities.
Solutions :
1-Addition of a glidant such as talcum or colloidal silica
2-Induced die feeders, which mechanically "force" the granulation down into the die cavities as they pass beneath the feed frame.

9. 7-Poor mixing
Sometimes, the lubricants and glidants are not thoroughly distributed. The flow of particles is then impaired, and the granules do not move efficiently into the dies. There is a tendency to minimize the mixing time during lubricant addition to prevent or reduce granule friability; however, inadequate mixing at this stage can result in unsatisfactory granulation flow.

10. 8-Punch variation
When lower punches are of unequal lengths- the difference may be only a few thousandths of an inch- the fill in each die varies because the fill is volumetric. Only a good punch and die control program can provide tooling of uniform dimensions.

11. 9-Hardness variation
Hardness variation is a problem that has the same causes as weight variation. Hardness depends on the weight of material and the space between the upper and lower punches at the moment of compression. If the volume of material or the distance between punches varies, hardness is likewise inconsistent.

12. 10-Double impression
This problem involves only punches that have a monogram or other engraving on them
It happens due to the rotation of the lower punch after compression and pushing the tablet out of the die where at this point it receives a new lighter impression .
Solution:
Installing antiturning devices in the presses.