Enantioselective, potentiometric membrane electrodes based on cyclodextrins: application for the determination of R-baclofen in its pharmaceutical formulation.

Two enantioselective, potentiometric membrane electrodes based on α- and γ-cyclodextrins were proposed for the assay of R-baclofen. The slopes of the electrodes were 59.50 and 51.00mV/pR-baclofen for α- and γ-cyclodextrin-based electrodes, respectively. The detection limits of the proposed electrodes were 7×10−9moll−1 for α-cyclodextrin-based electrode and 1.44×10−10moll−1 for γ-cyclodextrin-based electrode. The enantioselectivity was determined over S-baclofen. The proposed electrodes can be employed for the assay of R-baclofen raw materials and its pharmaceutical formulation, Norton-Baclofen® tablets. The surfaces of the electrodes are stable and easily renewable by polishing on alumina paper.