PROBLEMS ASSOCIATED WITH TABLET MANUFACTURING

Hello dear pharma bloggers

This is blog is aimed to cater the needs of those pharma fresher graduates who have just completed their graduation and looking to find their future in the phrama industry rather than higher education. If you seem to have interest in the production department, or R & D you need to have a keen knowledge of tablets.

Our team ASSIMILATORS have made a small attempt, I hope you all would like this.

Please follow these links before reading this blog, they include a brief note on introduction and tablet processing excipients.

http://www.pharmainfo.net/nandini/blog/introduction-tablets

http://www.pharmainfo.net/narmadha/blog/formulation-excipients-tablets

With the development of technology, the production process had become more simplified and more mechanized; the complexity of a tablet punching process has increased. But relatively reducing the problems associated with the manufacturing process

In olden days tablets were initially punched on small scale with hand operated machines, which suffered the problem of varied strength and integrity,

(1)hand operated small scale production machine

(2)medium scale production automated tablet punching machine

(3) (large scale automated fast tablet punching machine.)

but now the tablet punching machines are all mechanized, the mechanical feeding of feed from the hopper into the die, electronic monitoring of the press, but still tablet process problem still persist.

Tablet processing problems can be due to the problem in the formulation or in the compression equipment, or both of them.

Thus we can classify the problems into following three types(4,5,6):

1. Problem due to excipient: chipping, picking, binding, sticking, mottling,

2. Problems during process: capping, lamination.

3. Problem due to machine: double impression.

So at ever y step of the tablet manufacturing process, utmost care should be taken to avoid defected tablet.

1) Problems due to excipient:

This can arise due to the inaccurate addition of excipients or errors in the granulation process. It includes: sticking, picking, binding, mottling.

O Picking:

o Picking happens when a part of the tablets gets sticks to the punch surface and gets eroded from the tablet surface

o This mostly happens with the upper punch. And if this is left unchecked then this may lead to weight variation too.

O Sticking:

o It refers to the sticking of the tablet material with the die walls.

o Due to this sticking with the die walls, additional force is required to eject the tablet form the die walls.

o Sticking also causes production of tablets with rough edges.

o If this problem persists, then this can cause chipping of the tablet.

o It produced unusual stress on the cam track and punch heads resulting in their damage!

O Binding:

o Binding is sticking of the tablet to the die and does not eject properly out of the die.

o It may be mainly due to lack of proper lubricant or less quantity of lubricant, or may be due to excess moisture in the tablet.

O Chipping:

o Chipping usually happens around the tablet surface, small pieces are broken out or chipped out of the tablet.

o It is mainly due to improper machine setting, like ejection of the tablet.

O Mottling:

o Mottling is uneven distribution of the colour on the surface of the tablet, with dark and light patches on it.

o It is mainly due to different colouration of the excipient or the degradation product of the tablet is coloured.

(7)

O Capping:

o Capping is a complete or partial separation of the upper or lower surface of the tablet horizontally, when the tablet comes out of the die.

o When the air is entrapped in between the tablet material in a die, and when the material gets compressed between the two punches, the air entrapped also gets compressed, but when the pressure is released on the tablet I.e. when the two punched move apart and the tablet ejects out of the die, the compressed sir expands and leads to capping.

O Lamination:

o It is similar to capping but here the tablet gets separated into layers.

o It can once again occur due to the air entrapment or due to the high speed of turret

(8)

(tablet capping and lamination)

O Double impression:

o It is seen when the tablet punches have engraving or monograms on it to be embossed on the tablet.

o When the tablet material comes into the die for the compression both the punches come in contact with the tablet material and compress it, the next step is ejection of the tablet from the die,

o During ejection process the lower punch travels a small distance down and then comes up to give a gentle push to the tablet, at this point when the lower punch moves down and comes up it moves in a swirlling motion, due to the free rotation when it comes in contact with the tablet for the second time to push it up it leaves another impression on the tablet. Which is leads to double impression.

o To avoid this key are to be used along the sides of the punches, so that it prevents rotation of the punches.

This blog is free from plagiarism.

Reference:

1. http://www.labequipmentsindia.com/product/image/2252.jpg

2. http://product-image.esuppliersindia.com/00431839/s/3/Tablet-Punching-Machine.jpg

3. http://www.gmpchina.net/image/p/gzpt1060.jpg

4. The theory and practice of industrial pharmacy by Leon Lacman, Herbert A Lieberman, Joseph L.Kang third edition, Varghese publishing house page no -311-314

5. Pharmaceutical Dosage Forms Tablets, Vol. 1, pg.no- 188-190

6. http://www.authorstream.com/Presentation/sabapathi-369361-problems-tablet-manufacturing-science-technology-ppt-powerpoint/

7. http://www.justice.gov/dea/programs/forensicsci/microgram/mg0206/mg0206_fig3.jpg

8. http://upload.wikimedia.org/wikipedia/en/2/27/Tabletfailure.jpg