Pediatric formulation development requires an understanding of the physico-chemical stability and the taste of the pharmaceutical drug product. Two model active pharmaceutical ingredients (compound X and compound Y) were used to develop a powder for reconstitution to a suspension and a solution dosage form after dilution with purified water. X-ray powder diffraction was used to monitor the physical stability of compound X in the suspension and high pressure liquid chromatography was used to monitor the chemical stability of compound Y in the solution. The most stable suspension (formulation T) and solution (formulation Z) were used to assess the change in taste-perception by different flavors using the Astree (TM) electronic tongue. The suspension was determined to be stable for 43 days and 21 days respectively at 5 degrees C and 25 degrees C/60% RH. Compound Y solution was chemically stable for up to 30 days at 25 degrees C/60% RH. The taste of the suspension was improved by Lemon and Cherry flavors. The taste of the solution was made better by Vanilla, Cherry, and Strawberry flavors. The significance of these results is that the e-Tongue can be used in the early stages of formulation development to eliminate flavors that do little to improve the palatability of a formulation. (C) 2012 Elsevier B.V. All rights reserved.