Effects of compounding and storage conditions on stability of pergolide mesylate.

The study focuses on investigating how temperature and light affect the stability of a drug called pergolide mesylate, when compounded in water-based substance, and stored for 35 days.

Research Methodology

• The researchers started by compounding pergolide into a formulation with a target concentration of 1 mg/mL.
• Portions of this compound were then stored in varying conditions:
  • At -20 degrees, 8 degrees, 25 degrees or 37 degrees Celsius without exposure to light
  • At 25 degrees Celsius with exposure to light
• The storage period stretched over 35 days.
• Samples were analyzed immediately after compounding and then on days 1, 7, 14, 21, and 35 of storage, using a technique called high-pressure liquid chromatography. Each sample was assessed three times.

Research Findings

• The concentration of pergolide in the formulation right after compounding averaged 1.05+/-0.086 mg/mL.
• Results highlighted that samples exposed to light at 25 degrees Celsius degraded excessively by day 14.
• Similarly, samples stored at 37 degrees Celsius had excessively degraded by day 21.
• By day 35, samples stored at 25 degrees Celsius without exposure to light had also declined excessively.
• The degradation revealed in change in color and in the appearance of degradation peaks in chromatograms, which are graphical representations of chemical analyses.

Conclusion

• The research concluded that pergolide mesylate was unstable when combined with water-based substances due to exposure to various storage conditions, particularly temperature and light.
• Due to its instability, the researchers advised that pergolide mesylate compounds in water-based vehicles should be stored in a dark container and away from light and refrigerated. They should not be used >30 days following their production.
• Any formulations that have changed color should be considered unstable and discarded due to chemical degradation.