For category 2 drugs, how long can they be kept in a refrigerator?

• A. 1 day
• B. 4 days
• C. 7 days
• D. 14 days

Answer: (B)

When a drug is reconstituted, its stability in the refrigerator depends on how the drug is classified. For category 2 drugs, the guidance is that once prepared, they can be stored at 2–8°C for four days. This limit comes from stability data and safety practice: even in the fridge, chemical degradation and potential contamination can occur over time, so a conservative four-day window protects potency and patient safety. Keeping it only one day would be unnecessarily restrictive, while seven or fourteen days would exceed what the stability data support. Always check the specific product’s labeling or pharmacy guidelines, and discard after the indicated time.