Stability of diluted dexamethasone sodium phosphate injection at two temperatures

Premature neonates with bronchopulmonary dysplasia frequently are treated with intravenous dexamethasone for their chronic lung disease. The injection volumes of the commercially available products often are too small to measure accurately. The objective of this study was to evaluate the stability over 28 days of dexamethasone sodium phosphate injection 4 mg/mL diluted with bacteriostatic NaCl 0.9% to 1 mg/mL.

Ten vials of dexamethasone 1 mg/mL were prepared from dexamethasone sodium phosphate injection, USP 4 mg/mL and bacteriostatic NaCl 0.9% injection. Five vials were stored at 4 degrees C and five at 22 degrees C. Dexamethasone was measured on days 0, 1, 3, 7, 14, 21, and 28 by an accurate, reproducible, and stability-indicating HPLC method. Samples were also inspected visually for precipitation or discoloration on each study day.

The samples retained at least 97.7 percent of the original concentration of dexamethasone sodium phosphate when stored at either 4 or 22 degrees C for 28 days. No discoloration or precipitation was observed.

Dexamethasone sodium phosphate injection 1 mg/mL in bacteriostatic NaCl 0.9% was stable for 28 days at 4 and 22 degrees C.