Appearance defects of Tablets during compression activity
‘Capping’ is the term used, when the upper or lower segment of the tablet separates horizontally, either partially or completely from the main body of a tablet and comes off as a cap, during ejection from the tablet press, or during subsequent handling.
It is partial or complete separation of the top or bottom of tablet due air-entrapment in the granular material.
Lamination / Laminating:
‘Lamination’ is the separation of a tablet into two or more distinct horizontal layers
It is separation of tablet into two or more layers due to air-entrapment in the granular material.
‘ Sticking’ refers to the tablet material adhering to the die wall. Filming is a slow form of sticking and is largely due to excess moisture in the granulation.
It is the adhesion of granulation material to the die wall
Small fine cracks observed on the upper and lower center surface of the tablets, or very rarely on the side wall are referred to as cracks.
It is due to rapid expansion of tablets when deep concave punches are used
‘ Chipping’ is defined as the breaking of tablet edges, while the tablet leaves the press or during subsequent handling and coating operation.
It is due to very dry granules
‘ Mottling’ is the term used to describe an unequal distribution of colour on a tablet.
It is either due to any one or more of these factors: Due to a colored drug, which has different color than the rest of the granular material (Excipient- related); improper mixing of granular material (Process-related); dirt in the granular material or on punch faces; oil spots by using oily lubricant.
‘ Double impression’ involves only those punches,which have a monogram or other engraving on them.
It is due to free rotation of the punches, which have some engraving on the punch faces
It is the removal of material from the surface of tablet and its adherance to the face of punch.