Processing problems in tablet manufacturing

Problems in tablet manufacturing

1. Processing problems in tablet manufacturing

2. Processing tablets in tablet manufacturing An ideal tablet should be free from visual defect or functional defect. In olden days tablets were initially punched on small scale hand operated missions, which suffered the problem of the varied strength and integrity.  With the modern evolution of industrial machinery, the tablet punching missions are mechanized.  However, the tablet processing problem still persists.  An industrial pharmacist usually encounters number of problems in tablet processing.  Majority of visual defects are due to inadequate fines or inadequate moisture in the granules ready for compression or due to defective machine setting. Functional effects are due to defective formulation. 

3. Capping Capping is a term used to describe the partial or complete separation of the top or bottom crowns of a tablet from the main body of the tablet. CAUSES : This is usually caused by air entrapment in a compact during compression and subsequent expansion of tablet on ejection from die. This may be due to improper drying of granules insufficient amount of binder large amount of fines in granulation REMEDIES: Remove fines through 100 or 200 mesh screen Proper drying of granules Increasing amount of binder Moisten he granule with hygroscopic substances such as PEG-4000. Poor finishing of dies/ deep concave punches

4. Lamination It is the separation of a tablet into two or more distinct layers. CAUSES : Presence of oily or waxy materials in the granules. Presence of too much of hydrophobic lubricant. Eg : Magnesium stearate Rapid decompression REMEDIES: Add absorbent and modify mixing process. use minimal amount of lubricant use tapered dies reduce the final compression pressure

5. Picking CAUSES : Picking is concerned when punch tips have engraving or embossing letters. excessive moisture in granules improper lubrication low melting point medication in high concentration may soften in high temperature. rough or scratched punch faces REMEDIES: Proper drying of granules Increasing lubrication by adding a little more amount of binder with high melting points. compress at room temperature and cool sufficiently before compression. polish punch faces design lettering as large as possible Picking is the term used when a small amount of material from a tablet is sticking to and being removed off from the tablet surface by a punch face. This occurs predominantly in upper faces of the punches.

6. Sticking This condition refers to the tablet material adhering to the die wall . Filming is a slow form of sticking and is largely due to excessive moisture. CAUSES : This may be due to improper drying of granules Excessive amount of binder Too soft granules hygroscopic granular material improper lubrication Too deep concavity of punches REMEDIES: Proper drying of granules proper lubrication reduce the amount of binder modify granulation and compress under controlled humidity. reduce concavity of punches increase pressure

7. Mottling Mottling is an unequal distribution of color on a tablet, with light or darker areas standing out in an uniform surface. CAUSES : This may be due to Improper mixing of coloured binder solution as the dye migrates to the surface of granulation while drying. coloured drug used with colourless/white excipients. Improperly mixed dye, especially during direct compression REMEDIES: Use appropriate colorants change the solvent system/ binder size reduction of granules. incorporate dry colour additive during powder blending step for proper mixing.

8. Chipping CAUSES : This may be due to Sticking on punch faces Too much binding might cause chipping Concavity too deep to compress groove of die worn at compression point REMEDIES: proper drying of granules increasing lubrication optimize binding by using binders reduce concavity of punches instead use flat punches Polish to open end, reverse or replace the die. Chipping is defined as the breaking of tablet edges, while the tablet leaves the press or during subsequent handling and coating operations.

9. Cracking In this condition, fine cracks are observed on the upper and lower central surfaces of tablets or very rarely on the sidewall are referred to as cracks. CAUSES : This may be due to Sticking on punch faces Too much binding might cause chipping Concavity too deep to compress groove of die worn at compression point REMEDIES: proper drying of granules increasing lubrication optimize binding by using binders reduce concavity of punches instead use flat punches Polish to open end, reverse or replace the die.