This article discusses a new method for the preparation of extemporaneous ibuprofen-based suspensions for use in paediatric patients. This method allows the preparation of extemporaneous suspensions up to concentrations of 200 mg/5 mL by using a liquid base named "Wagner." A comprehensive physicochemical stability study was conducted on the formulation at a drug concentration of 200 mg/5 mL by performing high-pressure liquid chromatography and Turbiscan analyses. Chromatographic analyses of the samples demonstrated the chemical stability of the active pharmaceutical ingredient in the base for more than 90 days when the formulations were stored at 4°C and 25°C. Visual and optical analyses evidenced a reversible, slightly creaming phenomenon when the formulations were stored at 4°C or 25°C restoring the initial suspension by simply shaking.