Tablet Production Interview Questions: Granulation, Compression Defects & Coating

Production (manufacturing) is the department that hires the largest number of pharmacy graduates. Most production interviews for tablets revolve around granulation, compression, coating and in-process checks. Here are the questions you should prepare.

Granulation

1. Why do we granulate powders?

To improve flow, compressibility and content uniformity, prevent segregation of ingredients and reduce dust.

2. What is the difference between wet and dry granulation?

Wet granulation uses a binder solution, followed by drying. Dry granulation (slugging or roller compaction) compacts powder without liquid – used for moisture- or heat-sensitive drugs.

3. What equipment is used in wet granulation?

Rapid Mixer Granulator (RMG) for mixing and granulating, Fluid Bed Dryer (FBD) for drying, multi-mill or co-mill for sizing, and a blender (octagonal or bin blender) for lubrication.

4. How do you check the end-point of granulation?

By ampere/power consumption reading of the RMG, granule consistency (the "snowball" or ball test by hand) and as per the validated time in the BMR.

5. What is LOD and why is it checked after drying?

Loss on Drying – the moisture content of granules. Too much moisture causes sticking; too little causes capping. It must be within the BMR limit.

Compression

6. Name the main parts of a rotary tablet press.

Hopper, feed frame, die table (turret), upper and lower punches, dies, pressure rollers (pre- and main compression), ejection cam and take-off blade.

7. What are tooling types B and D?

They are standard punch sizes. D tooling has a larger head and barrel and is used for bigger tablets needing higher force; B tooling is for smaller tablets.

8. Explain common tablet defects.

9. What in-process checks are done during compression?

Appearance, average weight, individual weight variation, thickness, hardness, friability and disintegration – at fixed intervals as per BMR.

10. What is friability and its general limit?

The tendency of tablets to break or chip on handling, tested in a friabilator. A common pharmacopoeial limit is not more than 1% weight loss.

Coating

11. Why are tablets coated?

To mask taste or odour, protect from moisture/light, improve appearance and identification, or control drug release (enteric or sustained release).

12. Name common film coating defects.

Orange peel (rough surface), twinning (tablets sticking together), picking, logo bridging, cracking and colour variation.

13. What parameters are controlled in a coating pan?

Inlet and exhaust air temperature, bed temperature, pan speed, spray rate, atomising air pressure and gun-to-bed distance.

GMP on the shop floor

14. What do you check before starting a batch?

Line clearance, equipment cleaning status label, calibration status, correct BMR and dispensed materials verified against it.

15. What is the role of a production officer?

Running the batch as per BMR, recording entries in real time, handling operators, reporting deviations and coordinating with QA and stores.