Stability of methylprednisolone sodium succinate in small volumes of 5% dextrose and 0.9% sodium chloride injections.

The stability of methylprednisolone sodium succinate in small volumes of 5% dextrose and 0.9% sodium chloride injections was studied. Vials of methylprednisolone sodium succinate (125-3000 mg) were reconstituted and added to 50- and 100-ml volumes of the two diluents. These piggyback solutions were visually inspected for the development of haze over a 24-hour period. A nephelometer was used to quantitate the development of turbidity with time. The effect of pH on haze formation was investigated, and infrared spectroscopy was used to identify the haze. Nephelometer readings were found to correlate well with visual inspections. The haze was identified as being formed by the precipitation of free methylprednisolone. The rate of change of turbidity was directly related to the pH. A 1.4-3.2 percentage-point increase in the free methylprednisolone concentration secondary to hydrolysis over the 24-hour period was noted. The duration of stability was variable among the investigated lots and concentrations. Nineteen of the 24 admixtures stored at room temperature remained stable and free of visible haze for at least 12 hours after preparation. For all dosage strengths of methylprednisolone sodium succinate studied, these data indicate that solutions can be made stable for at least 12 hours by selecting the appropriate volume of diluent.