Purpose: To assess the stability of an extemporaneously compounded oral suspension of bosentan from commercially available tablets for a period of 1 month.
Methods: A 6.25 mg/mL oral suspension of bosentan monohydrate was prepared from Tracleer tablets. The bosentan suspension was then evenly divided between 2 light-resistant prescription bottles and stored in the dark either under refrigeration (4-8°C) or at controlled room temperature (21-26°C). The suspensions were assessed for physical changes (ease of resuspendability, change in color, change in odor), and samples were drawn immediately after preparation and on days 0, 1, 3, 7, 10, 14, 21, 28, and 31. Samples were analyzed at each time point by high-performance liquid chromatography (HPLC) utilizing a reversed-phase column with chemical stability defined as the retention of at least 90% of the initial intact bosentan concentration measured.
Results: No change in suspendability, color, or odor of the compounded bosentan suspensions was noted throughout the storage period. Furthermore, regardless of storage conditions, the oral suspension of bosentan retained at least 94% of the active pharmaceutical ingredient for 31 days after preparation.
Conclusion: The results of our study indicate that a 6.25 mg/mL bosentan oral suspension stored in the dark under refrigeration and at room temperature maintains physical and chemical stability for 1 month.
Keywords: bosentan; compounded; pulmonary arterial hypertension; stability; suspension.