Exploring Diverse Molecular Interactions of Some Amino Acids in the Aqueous Solution of an Antiemetic Drug (MCH) through Physicochemical and Computational Approaches

In this research, the physicochemical properties of some amino acids, namely, l-alanine (l-Ala), l-valine (l-Val), and l-leucine (l-Leu), have been determined in various concentrations (0.001, 0.003, and 0.005 mol. kg^–1) of an aqueous metoclopramide hydrochloride (MCH) solution at five different temperatures (293.15 to 313.15 K) and pressure at 0.1 MPa. The research focused on assessing volume-related properties, including apparent molar volume (ϕ_v), limiting apparent molar volume ϕv0, limiting apparent molar volume of transfer (Δϕv0), and hydration numbers (n_H), by analyzing density data. The viscosity data have been fitted into the Jones–Dole formula and transition state treatment to estimate the viscosity A and B coefficients, dB/dT values, and activation parameters Δμ10≠,Δμ20≠,TΔS20≠,ΔH20≠. Conductance and tensiometric properties were also measured. Amino acids have the potential to break the structure of aq. MCH solution, based on experimental values for Hepler’s constant (∂ϕE0/∂T)P, derivatives of the B coefficient (dB/dT), and Walden Product (Λm0η0). Additionally, UV–vis and computational studies have been conducted to identify the various interactions present between the solute and solvent. The primary aim of this study is to understand the role of some amino acids in a water-based solution containing metoclopramide hydrochloride (MCH), which could offer significant insights for the pharmaceutical sector.