This study examines the pharmacokinetic parameters of a newly optimized drug formulation compared to a marketed formulation to determine if it offers superior bioavailability, reduced side effects, and improved patient compliance. Pharmacokinetics is crucial in understanding drug actions and is essential for assessing the effectiveness and safety of immunosuppressive drugs. Key pharmacokinetic parameters, such as clearance, half-life, and protein binding, impact drug efficacy and toxicity. Advances in drug delivery systems, guided by pharmacokinetic principles, have led to optimized formulations that improve bioavailability, therapeutic efficacy, and patient compliance. However, challenges such as poor bioavailability, variable drug absorption, stability issues, targeted delivery, drug resistance, and patient compliance persist. Innovative strategies, such as nanotechnology-based systems, advanced drug delivery devices, prodrug strategies, bioavailability enhancers, personalized medicine, and novel polymers, are needed to address these issues. Comparing optimized formulations with marketed products through pharmacokinetic studies can help pinpoint improvements in therapeutic outcomes.