Is methyl salicylate the perfect organic solvent for caffeine?

In this article, detailed physicochemical characterization of caffeine + methyl salicylate mixtures is performed based at solubility, density, speed of sound and viscosity measurements in a temperature range from T = (293.15-313.15) K. The thermodynamic parameters have been evaluated from experimental measurements, and results are additionally supported by molecular dynamic simulations. From obtained thermodynamic properties, it was discussed how the caffeine presence influences the molecular interactions and methyl salicylate solvent clathrate-like structural organization. The comprehensive investigation confirmed the absence of caffeine self aggregates in methyl salicylate solvent. The solubility of caffeine in methyl salicylate is 69% higher than in water at T = 293.15 K, while at T = 313.15 K it is lower by 7%. The dissolution of caffeine in methyl salicylate occurs with heat absorption and an increase in the order of the system. The methyl salicylate choice as a solvent is important because caffeine and methyl salicylate could be found in pharmaceutical and cosmetical formulations for topical and transdermal caffeine delivery.