Gel Filtration of Solubilized Systems. VII. Temperature Effect on the Solubilization of Ethylparaben in Hexaoxyethylene Lauryl Ether Micelles

元データ 1984-08-25 社団法人日本薬学会


The effect of temperature on the solubilization of ethyl p-hydroxybenzoate (ethylparaben) in hexaoxyethylene lauryl ether (C_<12>E_6) micelles was examined by the gel filtration method using Sephadex G-200. The values of standard Gibbs energy (ΔG^〓), enthalpy (ΔH^〓) and entropy (ΔS^〓) changes for the micellar solubilization of ethylparaben were calculated, together with the interaction energy parameter (ω). The negative values of ΔH^〓 and ω showed that there is an interaction between the phenolic OH group in ethylparaben and the polyoxyethylene groups in the C_<12>E_6 micellar phase. The positive values of ΔS^〓 suggest that the alkane moiety of ethylparaben is incorporated into the hydrocarbon core of C_<12>E_6 micelles. These results showed that both enthalpy and entropy effects control the micellar solubilization of ethylparaben.


東野 武郎 School Of Pharmaceutical Sciences University Of Shizuoka
五島 綾子 Shizuoka College Of Pharmacy
東野 武郎 Shizuoka College of Pharmacy
遠藤 文男 Shizuoka College of Pharmacy