SOP for Operating a Fluidized Bed Dryer (FBD)

In short: This illustrative SOP template covers pre-use checks, operation, in-process sampling, product transfer, bag inspection, and records for a fluidized bed dryer in tablet production. Use the equipment instructions and approved batch record for all operating settings and endpoints. The example’s pneumatic pressure range has no unit and must be confirmed before use.

Objective

Describe controlled checks and operating steps for a fluidized bed dryer (FBD) used in tablet production.

Scope

This example applies to an FBD installed in a production department. Complete the equipment name, unique ID, manufacturer, model, and site-specific product and process references in the approved local procedure. This template does not establish drying temperatures, airflow settings, pressure limits, time limits, sampling frequencies, loss-on-drying limits, or process endpoints.

Responsibilities

Example in-house criterion (not a pharmacopoeial requirement): A Production Officer or Executive supervises the operation. An in-process quality assurance (IPQA) Officer or Executive verifies the required checks. The Head of Production ensures that trained personnel follow the approved procedure and batch record.

Regulatory and process context

For U.S. drug CGMP, 21 CFR 211.100(a)–(b) requires approved written production and process-control procedures, documentation at the time of performance, and recording and justification of deviations. Section 211.110(a) requires written procedures for appropriate in-process controls and tests on samples from each batch. Sections 211.63 and 211.67 address suitable equipment and written cleaning and maintenance procedures. These rules do not supply operating settings for a particular dryer or product.

For EU GMP, EudraLex Volume 4 Annex 15 (2015), §§3.1–3.14 and 5.7, addresses qualification of equipment and validation of processes using documented, product-specific process knowledge and justified parameters. Follow the applicable local requirements and the approved manufacturing instructions for the site and product.

General instructions

Example in-house criterion (not a pharmacopoeial requirement): Before use, check the equipment status label and cleaning release; confirm line clearance and the product, batch, and process stage; inspect the bowl sieve, finger bag, retarding chamber and bowl; and verify that parts are fitted in accordance with the equipment instructions. Keep each FBD bag identified and stored in the site’s approved manner. Use a dedicated bag for a product only if that is the approved site changeover strategy.

The source procedure also directs operators to check the steam filter and confirm that the FBD trolley’s earthing connection touches the dryer. Include only the utility and bonding checks defined for the specific equipment and site.

Equipment and batch details

Complete the equipment ID and manufacturer/model details in the controlled master SOP. Before operation, confirm that the equipment has current approved status and that the product, batch number, stage, and process instructions match the approved batch manufacturing record (BMR).

Procedure

Pre-start checks

1. Confirm that the equipment and area are released for the intended batch and that line clearance is complete under the approved site procedure.
2. Check the cleaned status label, bowl sieve, FBD bag, retarding chamber, bowl, trolley, utility connections, and other checks listed in the equipment instructions. Do not use a damaged, incorrectly fitted, unidentified, or unreleased component.
3. Confirm the selected FBD bag is the one specified for the process. The source procedure proposes using a dedicated bag for each product and storing bags in labelled bins; treat this as an example in-house criterion and follow the approved changeover and bag-handling procedure.
4. Affix the site’s controlled activity/status label with the product, batch, stage, and other required identification. Notify IPQA for the required line-clearance verification before starting the operation.

Bowl locking and operating parameters

Position the bowl and retarding chamber as directed by the manufacturer. Lock the bowl using the approved pneumatic sequence. This example SOP states a pressure of “2.5 kg to 3.5 kg” for locking, but gives no pressure unit, gauge, or equipment reference. Do not use that range until it is confirmed for the installed machine.

Use only the approved BMR and equipment instructions for inlet-air temperature, airflow or other machine controls, drying time, and product-specific process parameters. This example SOP says to adjust the timer according to the BMR and to adjust steam for the required inlet temperature, but it does not provide product-specific values.

Drying operation

This example SOP says to open the steam valve and bypass valve initially to drain condensate, then close the condensate valve and adjust steam to obtain the required inlet temperature. Follow that sequence only if it matches the approved instructions for the installed steam circuit and dryer.

1. Start and operate the dryer using the approved equipment sequence and BMR settings. Check that the bowl and outlet are seated and that the equipment has no air leakage that could affect the process.
2. If the approved process requires loading material into a bowl and positioning a trolley in the dryer, carry out that sequence under the equipment instructions. This example SOP says to charge the powder into the FBD bowl and push the trolley into the dryer.
3. Monitor the process at the points and frequency specified in the BMR. This example SOP says to check the steam-indicator valve during operation and to take granule samples intermittently from sampling points for loss-on-drying (LOD) testing; do not choose the indicator criteria, sampling points, frequency, test method, or limit from this template.
4. Complete drying only when the approved batch record’s endpoint is met. This example SOP says to shut off steam after operation and air-dry the material until it reaches ambient temperature, but gives no endpoint or measurement method.
5. Shake the FBD bag and allow material to settle only where the approved equipment and process instructions require it. This example SOP’s following instruction to remove, rack and reset the product container before further drying is unclear; do not use that step until the intended sequence is confirmed.
6. After the BMR authorises completion, release pressure and unlock the bowl using the equipment instructions. Remove the product or transfer it to the next process step under the approved material-handling procedure.

Bag inspection, status, and cleaning

Example in-house criterion (not a pharmacopoeial requirement): Inspect the FBD bag before and after use for holes, tears, open seams or stitches at the fingers, and damaged corners. Record the result in the controlled bag-use record. Remove damaged bags from use under the site’s material-control procedure.

After product transfer, affix the site’s “To be cleaned” status label, enter the operation in the equipment log, and clean the FBD using the current approved cleaning procedure. Do not return the dryer to use until its cleaning and release requirements are complete.

Records and retention

Example in-house criterion (not a pharmacopoeial requirement): Complete the equipment log with the equipment ID, product and batch, stage, date and time, operator and verifier, BMR reference, key required process observations, sampling and LOD results or cross-references, deviations, bag inspection result, and equipment status after operation. Use controlled records for FBD bag inspection and use.

Retain batch-specific GMP records at least one year after expiry of the respective product batch. EU GMP Part I Chapter 4 §4.11 requires batch documentation to be retained for one year after expiry or at least five years after Qualified Person certification, whichever is longer. 21 CFR 211.180(a), current eCFR edition (2026), requires at least one year after expiry for production, control, or distribution records specifically associated with a drug-product batch. Apply any longer requirement under applicable law or the marketing authorisation.

Related procedures

• Operation of an oscillating granulator
• Operation and cleaning of a tablet compression machine
• Critical quality attributes in tablet compression

Frequently asked questions

Can this template set the drying temperature or time?

No. Use the equipment instructions and approved product-specific BMR. This template does not establish setpoints, process limits, or endpoints.

Does the “2.5 kg to 3.5 kg” range define pneumatic pressure?

This example does not state a pressure unit, so the value is incomplete. Confirm the unit and permitted range against the installed FBD documentation and approved qualification before use.

How should LOD samples be collected during drying?

Follow the approved BMR and in-process sampling procedure for the product. They should define the sampling points, frequency, test method, and acceptance criteria.

References

1. United States Electronic Code of Federal Regulations. 21 CFR §§211.63, 211.67, 211.100(a)–(b), 211.110(a)–(c), and 211.180(a), current eCFR edition (2026; accessed 19 October 2026). §211.63; §211.67; §211.100; §211.110; §211.180.
2. European Commission. EudraLex Volume 4, EU Guidelines for Good Manufacturing Practice, Annex 15: Qualification and Validation (2015; applicable from 1 October 2015), §§3.1–3.14 and 5.7. Official Annex 15 PDF.
3. European Commission. EudraLex Volume 4, EU Guidelines for Good Manufacturing Practice, Part I, Chapter 4: Documentation (January 2011), §4.11. Official Chapter 4 PDF.