Answer
It may be covered with a breathable bandage after the gel dries, but not with an airtight occlusive dressing.
Sources for this answer
- Diclofenac diethylamine (Motusol) 1.16% Gel — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.