Development of a safe and versatile suspension vehicle for pediatric use: Formulation development.

This project aimed to develop a suspension vehicle specifically designed for pediatric use. Excipients were selected according to their safety and recorded use in pediatrics. Two suspension vehicles were formulated at neutral and acidic pH. A few compositions were defined, and their physicochemical properties assessed and compared to readily-available commercial vehicles. As required for a multidose oral formulation, an antimicrobial effectiveness test was conducted according to the USP. Different microbial strains were inoculated individually in each formulation and their concentrations monitored for 28 days. Propionic acid proved to be an effective preservative against all tested strains at pH 4.5. All tested preservative failed the test at pH 7.5. The final version of the novel vehicle presented a pH of 4.5 and a viscosity of 85 cP at 25 °C. A clear shear-thinning behaviour could be observed. These properties warranted an adequate physical stability and resuspendability, when tested with prednisolone and acetaminophen tablets. A slight reduction of the viscosity was reported when stored at room temperature, but the pH remained constant for 180 days in refrigerated conditions and at room temperature. The final result is a ready-to-use compounding vehicle, containing minimal excipients, safe for children's use and stable for 6 months.