Tablet Lamination

Tablet lamination is most common problems observed during compression of tablets it is often misconceived with capping problem firstly, we need to understand Lamination to rectify it as both Capping and Lamination have different reasons and different rectifications . Main reason for Lamination is attributed to presence of Bands/Cracks in tablet whereas presence of air in capping .

Lamination is whenever tablet is breaking or separating anywhere rather than top if is separating from top it is capping . Before rectifying be sure it is lamination Where is the problem Surface of tablet, below the top layer or Bottom of tablet .

Root causes of Lamination

1. Excessive quantity of dry Granules is an reason of Lamination which may be due to bad drying or inefficient equipment selection for drying purpose .
2. Excessive fines is another major reason of lamination which may be due to high speed of milling.
3. Less binder used in formulation could also leads to lamination as less binder is unable to hold the tablet compact .
4. Less thickness of tablet at precompression is also a reason for lamination as one tablet is formed at precompression and one at main compression and bi-layer tablet is formed .
5. Ejection problem leads to lamination (Ring in the die) .

Compressing the tablet too thin The only common factor between Capping and Lamination Usually occurs at precompression causing the tablets to compress in layers And the Layers will separate as tablets cool or the bottom layer will separate from top during ejection .

Ejection issues could lead to Lamination . 

1. If Ejection cam is not set up properly  and not leveled with Ejection blade it will damage the tablet and ejected tablet will be misunderstood as Lamination . And the Problem is actually of Ejection .
2. Ring in the die is another major governing factor sometimes due to continuous compression cycles Rings are formed in die during compression the tablet are compressed in these rings And will separate during Ejection causing Lamination Problem can be rectified either by changing tooling or by changing Punch penetration and Compressing somewhere else other than Ringed Surface .

Due to entrapment of air in tablet the pressure applied during compression is not uniform on whole tablet which leads to serious ejection problems and Lamination in Flat dies could be rectified using Tapered dies .

• Install dies with 6 mm taper .
• Compress tablets at 2.0 mm punch entry i.e Upper punch penetration means upper punches will meet with lower punches 2.0 mm inside the die.
• Target thickness is 6 mm .
• Adjust lower punches 8 mm below to obtain target thickness .
• Lower now the compression will occur at 6.0 mm i.e Right below the taper .
• Outcome will be residual air at top of tablet is removed and Lamination problem is rectified .