Physicochemical properties and the nature of interaction of drug-amino acid have been investigated from the experimentally measured values of densities, ρ, ultrasonic speed, u and viscosities, η of l-arginine and l-histidine in aqueous-semicarbazide hydrochloride (1 wt% and 2 wt% semicarbazide hydrochloride in water, w/w) solvents over the temperature range of 293.15 K to 318.15 K at an interval of 5 K and at atmospheric pressure. From the experimental densities, the apparent molar volume, Vφ, limiting apparent molar volume, Vϕo and transfer volume, Vϕ,tro were obtained. Further from the ultrasonic data, thermo-acoustical parameters, such as apparent molar compressibility, Ks,ϕ, limiting apparent molar compressibility, Ks,ϕo and transfer compressibility, Ks,ϕ,tr° have been evaluated. The viscosity data have been used to determine Falkenhagen Coefficient, A, Jones-Dole coefficient, B, free energy of activation of viscous flow per mole of solvent, Δμ1o# and solute, Δμ2o#, entropies, ΔSo# and enthalpies, ΔHo# of activation of viscous flow. The results have been interpreted in terms of plausible molecular interactions. The cosphere overlap model has been used to interpret the positive Vϕ,tro values. These amino acids act as structure maker in aqueous-semicarbazide hydrochloride solvents.