Edge Erosion in Pharmaceutical Tablets

 Description of the problem: Corrosion and irregularity in the edges of the tablets .

 

Reasons:

 1: fine powder.

2: The punches are worn out.

3: The moisture of the powder is low.

4: Hardness is low.

5: The distribution of powder is uneven .

6: Separating the powder in the hopper or while using a vacuum loader.

7: tablets breackadge in a scraper.

8: There are differences in the lengths of lower punch.

 

Solutions:

1: Reduce the machine speed.

2: Increase Hardness.

3: increase press the penetration wheel.

4: be sure for the differences between the pre- and main compression wheels.

5: Set the scraper correctly.

6: Buy punches from an approved place.

7: Adjust the moisture of the powder.

Reasons related to the coating solution.

The percentage of polymer in the solution is low, or it is possible to change the type of polymer.

 

Reasons related to the coating process

1: Use a high drum speed at the beginning of spraying, and you must spray at a low drum speed so that the tablets take a suitable film layer that gives their edges durability in the beginning. (Decrease the drum speed)

2: Spraying at a very low rate, which gives an opportunity for the tablets to rotate without even spraying for a long period. The spraying must be at an appropriate rate to cover the tablets in the shortest possible time and give the first film layer. (low spray rate) (increasing the spray rate)

3: The patch size is not appropriate with the machine’s capacity, meaning that the patch size is small compared to the capacity. (increase the patch size)

4: The type of baffles is not suitable. (Change the type of baffles)

5: The pattern air is not suitable and the solution does not cover the tablets. (poor pattern air setting) (increase pattern air)

6: Very high temperature and losing a lot of droplets during the spraying process. (reduce the temperature)

7: The distance between the guns and the tablets is large and the solution does not reach the tablets regularly. (choose the correct level of distance for tablets to guns)

 

Read also:

• Scuffing in Tablet Coating
• Cratering in Tablet Coating
• Pharmaceutical Coating Process Scale-up Techniques