Preparation and Physico-Chemical Stability of Dexamethasone Oral Suspension

Abstract Background Dexamethasone is commonly used to treat a wide variety of diseases including oncological disorders. The aim of this study was to propose a liquid formulation of dexamethasone. Therefore we have developed and assessed the stability of a 5 mg/mL dexamethasone oral suspension. Methods A stability-indicating analytical method, using HPLC-UV, was developed and fully validated according to well-recognized international guidelines. The dexamethasone suspension was prepared using dexamethasone acetate powder and Ora-Sweet® plus Ora-Plus® suspending vehicles (1:1, v:v). Compounded oral suspension were packaged in amber type I glass bottles. In order to assess physical and chemical stability of dexamethasone in oral suspension, six batches of the formulation were prepared and stored at 4±2 °C or at 21±3 °C. Physical parameters (appearance, pH) were assessed as well as dexamethasone content, at day 0, 7, 14, 30 and 60. Results The mean dexamethasone concentration of the compounded oral suspensions was equal to 5.07±0.17 mg/mL. No colour modifications, precipitate or suspending troubles was observed throughout the storage period and the pH of the oral suspensions was decreased slightly, from 4.41±0.01 to 4.20±0.02. According to the dexamethasone content determined by HPLC-UV, whatever storage condition was used, no significant degradation of dexamethasone occurred over the 60 days of the study period. Conclusion Dexamethasone oral suspension prepared according to our conditions is stable over 60 days under regular storage temperatures (at 4±2 °C or at 21±3 °C).