Until now, drug formulations are still among the most important inventions, and ongoing research is being done to enhance their acceptability and efficacy in a variety of patient populations, as shown in both adults and pediatrics. Both age groups differ in a number of ways when it comes to the pharmacological element and therapy, including their aptitude for administering pharmaceuticals, how they respond to negative drug reactions, how they prefer to taste medications, and a host of other factors. Particularly, pediatrics and their pharmaceuticals require top priority due to the fact they must match and coincide with their age, size, physiological needs, and therapeutic requirements. This calls for addressing and elevating variations in these areas, particularly in pharmacokinetics, pharmacodynamics, formulation development, and regulation. This review explored these variations through a list of potentially-harmful medications for pediatrics presented in tables, as well as their uptake in adverse drug reactions than that of adults and pharmacodynamic differences, leading to the utilization of the physiologically-based Pharmacokinetic (PBPK) model for DDI prediction and evaluation model on pediatric-pharmacokinetic DDIs to assist in the safety and acceptability of commercially-available pediatric drug formulations.