OBJECTIVES:The effect of water-soluble polymers polyvinylpyrrolidone(PVP) and polyethylene glycol(PEG)on the complexation of drugs with β-cyclodextrin were investigated.METHODS:the thermodynamic properties of drugs in aqueous β-CD solution and in aqueous solut.RESULTS:The maximum solubilization concentration of PVP or PEG appeared from 1.5g.L－1 to 3.0g.L－1.At this low concentration,PVP or PEG had insignificant effect on the viscosity of the aqueous β-CD solution.The solubilising effect ofβ-CD on chloramphenicol was improved by 15% when containing 2.5g.L－1 polyethylene glycol in the solution and on vitamininum B2by 98%when containing 2.5g.L－1 polyvinylpyrrolidone.In aqueous solutions water-soluble polymers were shown to increase the solubilising effect of β-CD on drugs.Additing of PEG or PVP to the aqueous complexation medium resulted in an increased negative enthalpy change,together with an increased negative entropy change.CONCLUSION：Water-soluble polymers were shown to increase the solubilising effect of β-CD on drugs.