What is a conservative beyond-use date for suspensions to prevent caking?

• A. 2 Weeks
• B. 1 Month
• C. 6 Months
• D. 3 Months

Answer: (B)

Beyond-use dating for suspensions centers on keeping the product physically stable and uniformly dosed as it sits on the shelf. In a suspension, the solid particles tend to settle over time. If the product is stored long enough, the settled material can form a dense cake that is difficult to re-disperse, leading to inconsistent dosing and poor uniformity of the active ingredient.

Setting a conservative BUD helps ensure the suspension remains easily re-suspendable and chemically safe for use within a practical timeframe. A one-month date provides a cautious balance: it limits the window for physical instability and potential microbial growth in a water-containing preparation, while still being long enough for patient use between refills. Shorter dates would increase waste and compounding frequency, whereas much longer dates would raise the risk of irreversible caking and instability.

So, one month is chosen as a conservative, appropriate BUD for suspensions to mitigate caking while remaining clinically practical.