At 40 degrees C, after 3 months and 6 months, the pH of a steroidal parenteral aqueous suspension are which values?

• A. pH 7.0 and pH 7.0
• B. pH 2.0 and pH 2.0
• C. pH 3.15 and pH 3.24
• D. pH 3.24 and pH 3.15

Answer: (D)

The main idea is that, under accelerated stability conditions (high temperature), a steroidal parenteral aqueous suspension can undergo hydrolytic degradation that produces acidic products. This acid generation makes the formulation drift toward a more acidic pH over time. At 40°C, you’d expect a small drop in pH as storage time increases, not a rise or a neutral stay.

The observed pattern shows the pH starting at 3.24 after 3 months and becoming slightly more acidic to 3.15 after 6 months. That slight drift toward lower pH aligns with acid-forming degradation products accumulating over time, which is why this set of values is the correct representation. Other patterns, such as remaining neutral or becoming less acidic, don’t fit the expected degradation behavior at elevated temperature.