# Why Tablet Manufacturing Area Has Negative Pressure

It is the common observation that primary tablet manufacturing areas like tablet granulation, compression, coating and mixing areas are maintained at negative pressure or at the low pressure as compared to the adjacent areas.

Like wise other powder processing formulations like dry powder suspensions, capsule filling & any other oral solid dosage form manufacturing areas where powder materials are handled are always kept at the negative pressure or at the low pressure as compared to the adjacent areas.

Did you ever think that why we maintain less pressure inside the primary manufacturing area for the tablet manufacturing or other areas which are involved in the processing of powder or granules dosage forms.?

To understand the facts of above mentioned scenario we must have to be familiar with the purpose and principle of air lock system.

## Purpose & Principle Of Airlock

One of the main and basic purposes of air lock systems is to prevent the cross contamination and protection of clean rooms.

We are familiar that a lock system works on the principle of differential pressure and air moves from the area of higher pressure to the lower pressure.

Case Study 1

Now we will discuss what will happen if we maintain positive pressure or if we maintain our core tablet manufacturing areas at the higher pressure as compared to the adjacent areas.

Explanation

Suppose our tablet manufacturing area has higher pressure like 30 Pascal and our airlock system is maintained at the less pressure as compared to the primary manufacturing area suppose it is 20 Pascal and our corridor is maintained at the 10 Pascal.

In the above mentioned case if we will open the door of primary manufacturing area the dust or fine powder particles generated from the powder processing activities will move from primary manufacturing area to the airlock system (as air move from high pressure to low pressure) and when we will open the door of corridor from airlock system the powder or dust from the airlock system will move toward the corridor.

In the corridor we have door of an other manufacturing area and inside of that area there is negative pressure so if we will enter from corridor into that area then this powder or dust from corridor will also move inside second manufacturing area and it will result in cross contamination of the product in the second manufacturing area.

Case Study 2

Now take the example where we have set the negative pressure inside of our primary manufacturing area.Suppose we have 10 Pascal in our primary manufacturing area 20 Pascal in our airlock system and 30 Pascal in the corridor and along with the corridor we have second facility where we also have the 10 Pascal.

In this case if we will open the door of primary manufacturing area towards the airlock, the air from airlock will move towards the primary manufacturing area &  if we enter from corridor and open the door of corridor the cleaned air from corridor will enter to the airlock system and when we will enter from airlock system to the primary manufacturing area the air will move from airlock to the primary manufacturing area so dust of the powder particles will remain inside the area.

In the same way if we enter from corridor to the second manufacturing facility the air from clean corridor will enter to the airlock system and from the Airlock to the second manufacturing facility & there will be no cross contamination.

## Conclusion

In nut shell we maintain table & other oral solid dosage forms manufacturing areas at native pressure or at low pressure as compared to the adjacent areas to prevent the cross contamination or to prevent the dust particles from coming outside.

Due to this reason we always maintain our primary manufacturing area of tablet & other oral solid dosage forms at the low pressure as compared to the adjacent area so whenever we enter from outside to inside the dust particle will not come outside and they will remain inside the area and will not contaminate or cross contaminate our product.

Image Credit

Image Source – Google | Image By – Gansons