The density measurements have been carried out for ternary aqueous solutions containing a fixed concentration (similar to 0.1 mol center dot kg(-1)) of alpha-cyclodextrin (alpha-CD) and varying concentrations (similar to 0.003 to similar to 0.21 mol center dot kg(-1)) of some local anesthetical drugs, namely procaine hydrochloride (PC center dot HC1), lidocaine hydrochloride monohydrate (LC center dot HC1) and tetracaine hydrochloride (TC center dot HC1) at 298.15 K. The density data are used to determine apparent molar volumes of the drug molecules in ternary solutions at finite concentrations (phi(v)) as well at infinitely dilute solutions (phi(0)(v)). Following the methods developed by Hoiland et al. as well by Jolicoeur et al. and using the infinite dilution volume values for the drugs in ternary and binary solutions and incorporating the equilibrium constant values for the complexation between alpha-CD and drugs, volume changes due to encapsulation or complexation have been estimated. It is observed that all the studied hydrochlorides exhibit high positive volume change due to complexation. The results are discussed in terms of host-guest interaction and structural specificity of guest molecules. (c) 2016 Elsevier Ltd.