How the Granulation Reconciliation Calculator works

Granulation reconciliation compares the weight of granules or powder recovered after granulation, drying and milling with the theoretical weight expected from the batch formula. It is the first stage reconciliation in a solid dosage batch, and the loss found here carries into every later stage.

The calculator gives the loss in kilograms, the percentage loss and the percentage yield from the theoretical and actual weights.

Video walkthrough

Granulation arithmetic

Example: 120.0 kg theoretical

The batch formula gives a theoretical weight of 120.0 kg. After granulation, drying, milling and blending, 116.1 kg of granules are recovered.

1. Loss = 120.0 − 116.1 = 3.9 kg
2. % Yield = 116.1 ÷ 120.0 × 100 = 96.75%
3. % Loss = 3.9 ÷ 120.0 × 100 = 3.25%

Whether this result is acceptable depends on the limit in your batch record. If it is inside the limit, the figure is recorded. If not, a deviation is raised.

Granulation yield limits

• Limits: use the yield limits in the approved master batch record. They come from process validation and history, and differ between wet and dry granulation and between products.
• Accounted losses: in-process samples, material retained for analysis and rejects should be weighed and listed, so the unexplained loss is clear.
• Moisture: compare weights on the same moisture basis. Water added and removed during granulation changes the weight without changing the dry material.
• Result above 100%: investigate. It usually shows a weighing error, a wrong theoretical weight or moisture gain.

Where granulation loss usually comes from

Common sources are material sticking to the mixer, granulator and dryer surfaces, fines lost to the dust collector, spillage during transfers and milling losses. Tracking the loss step by step, for example after drying and after milling, shows which operation contributes most and where a change in practice will give the biggest improvement.

Granulation reconciliation errors

• Comparing wet and dry weights as if they were the same basis.
• Leaving samples and rejects out of the record.
• Using the planned batch weight instead of the weight that was actually dispensed.
• Ignoring a yield above 100%.
• Applying one blanket limit to every product.

If granulation yield is outside the limit

Start by checking the numbers before the process. Confirm that the theoretical weight matches the quantities actually dispensed, that every container was weighed on a calibrated balance and that the moisture basis is the same on both sides. Then look at the physical losses in order: residue in the granulator and dryer, the dust collector bag or filter contents, spillage records and milling losses. Weigh the recovered residues where possible. A documented recovery of material from the filters and equipment often explains a large part of the difference, and the rest is investigated as a deviation. See How to Investigate a Batch Reconciliation Failure.

Standards and references

The checks on this page relate to the documents below. Standards are revised from time to time, so confirm the current edition and follow your own approved procedures.

• 21 CFR 211.103, Calculation of yield
• 21 CFR 211.188, Batch production and control records
• 21 CFR 211.192, Production record review
• EU GMP Part I, Chapter 5, Production

Questions on granulation reconciliation

What causes granulation loss in tablet manufacturing?

Material on equipment surfaces, fines lost to dust collection, and spillage during transfers.

How do I calculate % yield after granulation?

Divide the actual weight recovered by the theoretical weight and multiply by 100.

Is a loss of a few percent normal?

Some loss is normal. What matters is whether it is inside the approved limit and explained.

Related tools and guides: Yield Above 100% · Batch Reconciliation Explained · Percentage Yield Calculator · Yield Loss Points Across Stages · Compression Reconciliation

By Sajjad Ahmad. For reference and education only; verify limits against your SOPs and the current pharmacopoeia. See the methodology.