Physicochemical, Spectroscopic, and Computational Insights into the Interactional Behavior of the Antihypertensive Drug Captopril in Aqueous and Normal Saline Systems

Captopril (CAP) is an antihypertensive drug commonly prescribed for hypertension and heart failure. In current research, the molecular interactions of CAP were examined in water and normal saline at various concentrations (0.001–0.010) mol·kg –1 and temperatures (295.15–315.15) K. To address this objective, we measured the densities (ρ), ultrasonic velocities ( c ), specific conductance (κ), and viscosities (η) of CAP in water and normal saline solvent systems. The experimentally determined data were used to evaluate various volumetric, acoustic, conductometric, and viscometric parameters. The outcomes obtained from these parameters were estimated in terms of drug-solvent and drug–drug interactions. The findings of physicochemical studies reveal strong binding affinity and structural organization behavior of CAP in water/normal saline, and these findings were supported by UV–visible and FTIR studies. The DFT studies were also carried out to evaluate various quantum parameters and visualize FMOs and ESPS of CAP and NaCl in water. The ADMET profile of CAP and molecular docking with the targeted protein 2YDM were studied to evaluate their pharmacokinetic behavior and binding efficacy. This investigation can help the scientific community to optimize drug design and drug delivery, leading to improved biological efficacy in the pharmaceutical and healthcare sectors.