Report on Nuvista Pharma Ltd (Part-8)

The Overall Tabletting Cycle is as Follows:

1. Hopper: Contains the granulated material which is to be tablatted
2. Feed frame: Fed by the hopper to hold the granule as it is fed in to the die.
3. Feed paddles: Ensures that the granule is keep agitated to correct filling of the die bore.
4. Draw-down Cam: The lower punch guide during the first part of the fill stage, adjustable to ensure that the die bore is over filled initially to allow accurate adjustment at weight control.
5. Weight control: The lower punch guide during the latter part of the fill stage, adjustable to ensure that as the punch rises, the correct quantity of granule remains within the die, and therefore the tablet dosage is correct.
6. Fill Station: The point where the die has been correctly filled.
7. Pre-compression rollers: This smaller roller gives the granule an initial pinch to remove as much air as possible before full compression takes place.
8. Main compression rollers: Applies full pre-determined pressure to the punches for the final formation of the tablet.
9. Compression Station: Where full compression of the tablet is achieved.
10. Ejection cam: This forms the lower punch guide during the ejection stage and is adjustable to ensure smooth ejection without damaging tablets.
11. Take-off blade: Fitted in front of the feed frame this deflects the tablet down the take-off chute.
12. Ejection station: This is the station where the tablet leaves the die for take-off.

 Take-off chute: the chute down which the tablet passes for collection and packaging

Problems during Processing and Compression:-

Tablet production may reasonably exhibit a number of defects during the process of developing formulation and in the routine manufacture of tablets, which are not desirable. These defects arise due to the following reasons:

1.      Wrong formulation

2.      Improper setting of tablet machine

3.      Processing error

Ø  Defects related to Tableting Process-

i) Capping It is due air-entrapment in the granular material.

ii) Lamination: It is due air-entrapment in the granular material.

iii) Cracking: It is due to rapid expansion of tablets when deep concave punches are used.

Ø  Defects related to Excipient-

iv) Chipping: It is due to very dry granules

v) Sticking

vi) Picking

vii) Binding

Capping:

Capping is the partial or complete separation of top or bottom layer of the tablets from the main body of the tablet.

Cause:

A. Problem of formulation

B. Problem of punch

C. Problem of die

D. Incorrect setting of tablet machine

Chipping:

      Chipping is the breaking of the edge of tablet during compression.

A.     Problem of formulation:

a) Excess moisture:

A certain percentage of moisture is often essential for good compaction. But excess moisture causes softening of granules and causes shipping problem.

Remedy:

- Proper drying

- Then addition of lubricant

    b) Lack of lubricant:

     Due to the lack of lubricants to the granules, the edge of granules may be broken down during compression.

Remedy:

Addition of sufficient amount of lubricant.

B.   Problem of punch:

            Chipping problem may arise due to the rough surface of the upper punch.

           Remedy:

-By changing upper punch

-The surface of the punch is polished by using lubricant.

C.  Problem of die:

           Serious sticking of the granules with the die wall during ejection causes chipping.

           Remedy:

1              Die wall is surrounded by tungsten carbide.

2              Inverting the die wall.

D.     Incorrect setting of tablet machine:

1        Improper setting of feed frame.

2        Incorrect adjustment of sweep off blade.

3        Improper setting of ejection knob.

Remedy:

1        Proper setting of feed frame.

2        Proper adjustment of sweep off blade.

3.   Proper setting of ejection knob.