Tablet coating pans are used in pharmaceutical industries for the film coating, sugar coating, enteric coating & drug coating of the tablets.

How much quantity of tablets can be loaded in the tablet coating pan depends on the capacity of the tablet coating machine or coating pan.

Tablet coating pans are available in different capacities and the capacity of tablet coating pan is always mentioned in liters instead of kilograms.

**Why**

Capacity of tablet coating pans is mentioned in liters because the capacity varies according to the density of the tablets.

So it is always mentioned in terms of the liters.

**How to calculate tablet coating Pan capacity **

To calculate the capacity of tablet coating pan we need two factors which are given as below,

- Brimful volume of pan
- Tablet bulk density

Bringfull volume is the volume of the water which can be added in the tablet coating pan up to its brim or upper edges.

In this article we will learn to calculate the capacity of conventional coating pans and the perforated tablet coating pan.

**Brimful volume **

We can calculate the brief full volume of conventional coating pan by adding the water into the conventional coating pan till its brim.

In case of the perforated tablet coating pan it is very difficult to fill the tablet coating pan till its brim so the coating pan’s brimful volume is always mentioned by the manufacturer in the document provided by them for perforated tablet coating pan.

**Bulk density **

Tablet bulk density depends on the weight,size, shape and dimensions of the tablet.Small tablets have high bulk density & occupy less volume in the tablet coating as compared to the large or oblong tablets.

Incase of round small tablets these are closely packed and there are less number of void spaces left that is why its density is high.

**Read details how to calculate tablet bulk density **

**Calculation **

Following formula is used to calculate the capacity of the tablet coating pan.

**Pan Capacity = Brimful volume × Tablet bulk density **

Suppose we have a tablet coating pan having a brief full volume of 600 liters and we want to calculate the capacity of this coating pan for a batch of tablets having bulk density 0.7g/ml.

Put the values in the above formula where we simply multiply the brimful volume of the coating pan with the bulk density of the tablets.

**Pan Capacity = 600 × 0.7 = 420 kg**

420 kilograms is 100% capacity of this tablet coating pan.

Now we will calculate maximum and minimum working capacity of this pan because 100% capacity is not utilized due to the fact that after weight gain tablets will fall out on door opening.

**Maximum Working Capacity **

For maximum working capacity of tablet coating pan we generally take 80 to 90% of total pan capacity.

**Reason**

As mentioned above if we add 100% tablets into the tablet coating pan after 3 to 5% weight gain the tablets will come out of the door when we will open the door of the tablet coating pan that is why we take 80% to 90% of maximum working capacity.

**Calculation**

Let’s calculate 80% working capacity for the above mentioned tablet coating pan.

As we are familiar that 100% capacity is 420 kilograms so 80% will be as

**80/100 × 420 = 336 kilograms **

**Minimum Working Capacity**

The minimum working capacity of a tablet coating pan is the capacity at which we can smoothly coat the minimum quantity of a specific batch in a tablet coating pan.

Usually we take 50% to 60 % as the minimum working capacity of a tablet coating pan.

**Reason**

If we take less than 50% then buffels will not be covered with tablets & the rotation of tablets will be affected and also affect the tablet quality.

**Calculation**

Let’s calculate 55% working capacity for the above mentioned tablet coating pan.

As we are familiar that 100% capacity is 420 kilograms so 55% will be as

**55/100 × 420 = 231 kilograms **

**Conclusion**

The capacity calculation of perforated & conventional tablet coating pan is always dependent on the volume of coating pan & bulk density of the tablets.The capacity of tablet coating pan is always taken in liters & it will be different for different products depending upon their bulk densities.

**Image Credit**

Image Source – Google | Image By Freund Vector

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