The Stability of Quetiapine Fumarate 10 mg/mL Compounded Oral Suspension in Ora-Blend and Ora-Sweet Vehicles Over Time at Two Temperatures

Purpose: Quetiapine fumarate (QF) is an atypical antipsychotic agent that is used off-label for the treatment of delirium in critically-ill children. QF is commercially available as immediate and extended-release tablets for oral administration. Although there is a published 40 mg/ml compounded suspension, this is not suitable for small doses, and there is no stability data available for QF compounded suspension. Therefore, the objective of this study was to evaluate the stability of 10 mg/mL QF compounded oral suspension in Ora-Blend (OB) vehicle and Ora-Sweet (OS) vehicle by analyzing drug contents, dissolved drug in selected vehicles, pH, visual appearance and odor at two temperatures up to 90 days. Methods: QF compounded suspensions (10 mg/mL) were prepared from QF commercial tablets in either OB or OS vehicle and were stored in plastic amber bottles at either 22°C or 2°C. At day 0, 7, 60 and 90, three bottles from each condition were used to prepare samples for the high-performance liquid chromatography (HPLC) analysis that was developed and validated. The drug contents were measured by directly mixing QF suspension with MeOH:H20 (v/v) and diluting the supernatant with MeOH after centrifugation to a detectable concentration for HPLC analysis. To measure dissolved QF, QF suspension was centrifuged and then QF in the supernatant was measured by HPLC. pH was measured by a pH meter, and physical characteristics were analyzed based on the changes in color and odor. Results: The QF drug contents in OB and OS for 90 days were not significantly different compared to day 0 at two temperatures. QF in OB remained dissolved over time at two temperatures, whereas QF in OS was precipitated out at day 7 and 90. The pH of both OB and OS preparations was consistent from day 0 to day 90. There were no significant differences in visual appearance or odor for both OB and OS preparations overtime at two temperatures. Conclusions Based on the results of drug contents, dissolved drug, pH and physical characteristics, QF compounded suspensions in OB were stable at two temperatures for up to 90 days. Compared to OS, OB is the better vehicle to prepare QF compounded suspensions. Keyword: Quetiapine fumarate, Stability testing, HPLC, Pediatrics