Stability of extemporaneously compounded dexamethasone in glass and plastic bottles and plastic syringes

Abstract

Background: Dexamethasone is widely used to treat rheumatic and endocrine disorders and chemotherapy-induced nausea and vomiting. A palatable, alcohol-free liquid formulation, with a suitable concentration to allow reasonable administration volume, is available only via extemporaneous compounding. Objective: To evaluate the stability of dexamethasone suspensions in commercially available vehicles (Oral Mix and Oral Mix SF) in various types of containers after storage at 25°C and 4°C for up to 91 days. Methods: Dexamethasone suspensions (1 mg/mL) were prepared in Oral Mix and Oral Mix SF and then transferred to amber glass and plastic prescription bottles and plastic oral syringes. Suspensions in all 3 types of containers were stored at 25°C; suspensions in glass and plastic bottles were also stored at 4°C. Samples were collected weekly from each container up to 28 days and then every 2 weeks up to 91 days. The samples were analyzed by a validated, stability-indicating high-performance liquid chromatography - ultraviolet detection method. A suspension was considered stable if it maintained at least 90% of its initial dexamethasone concentration. Changes in colour, taste, odour, precipitation (and ease of resuspension), and pH were used to assess physical compatibility. Results: All suspensions maintained at least 96% of the original concentration for up to 91 days with storage at 25°C or at 4°C. No notable changes in colour, taste, odour, precipitation, or pH were observed over the 91-day period. Conclusion: Dexamethasone suspensions (1 mg/mL) in Oral Mix and Oral Mix SF, stored in amber glass or plastic bottles or plastic syringes at 25°C or in amber glass or plastic bottles at 4°C can be expected to remain stable for up to 91 days.