1. Purpose

To define the procedure for proper cleaning of the Dry Heat Sterilizer (DHS) to prevent contamination and ensure compliance with GMP requirements.

2. Scope

This SOP is applicable to the cleaning of DHS used for depyrogenation/sterilization of vials, ampoules, and glassware in sterile manufacturing.

3. Responsibility

• Production Operator/Technician: Perform cleaning as per SOP.

• Production Supervisor: Verify cleaning and ensure record keeping.

• QA: Review and approve cleaning records, perform line clearance.

4. Materials & Cleaning Agents

• Lint-free sterile wipes/cloth

• 70% IPA (filtered through 0.2 µm filter)

• Approved cleaning detergent (if required)

• Sterile water for rinsing

• Cleaning logbook/record

5. Procedure

5.1 Preparation

1. Ensure DHS is switched OFF and cooled to safe handling temperature.

2. Display “UNDER CLEANING” status board on DHS.

3. Gather required cleaning materials.

5.2 Internal Cleaning

1. Open DHS door using aseptic precautions.

2. Remove any residual glassware or debris.

3. Wipe internal surfaces (walls, trays, racks, sensors) with sterile lint-free wipes soaked in 70% IPA.

4. Pay special attention to corners, joints, and air filters (without damaging them).

5. If heavy residue is observed, clean first with approved detergent solution, rinse with sterile water, and finally wipe with 70% IPA.

5.3 External Cleaning

1. Wipe the exterior surfaces of DHS with sterile wipes soaked in 70% IPA.

2. Clean control panels with a slightly damp sterile wipe (do not spray directly).

5.4 Post-Cleaning Activities

1. Allow the unit to air dry.

2. Inspect cleaned DHS for residues, stains, or damage.

3. Affix “CLEANED” status label with date, time, and operator signature.

4. Record cleaning activity in the DHS Cleaning Logbook.

6. Cleaning Frequency

• Routine: After each batch operation.

• Deep Cleaning: Weekly (using detergent + sterile water + IPA).

• Unscheduled: If contamination, spillage, or residue is observed.

7. Precautions

• Ensure DHS is cooled before cleaning.

• Use only validated cleaning agents.

• Do not damage sensors, HEPA filters, or temperature probes.

• Always use sterile lint-free wipes.

8. Documentation

• Record date, time, DHS ID, cleaning agent used, operator/supervisor signatures.

• Maintain records as per GMP documentation practices.

9. References

• Manufacturer’s Operating Manual

• EU GMP Annex 1

• USP <1211> Sterilization and Sterility Assurance of Compendial Articles