Synthesis of ethylenediamine linked beta-cyclodextrin dimer and its analytical application for tranilast...

A synthesis of beta-cyclodextrin (beta-CD) dimer, containing two beta-CD moieties that are linked through their sides by ethylenediamine, was presented. The dimer was characterized by means of IR, (1)H NMR, (13)C NMR, and elemental analysis. The inclusion complexation behavior of beta-cyclodextrin dimer with tranilast was studied in an aqueous KH(2)PO(4)-citric acid buffer solution of pH 2.00 at room temperature by spectrofluorimetry. Based on the significant enhancement of fluorescence intensity of tranilast, a spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of tranilast in bulk aqueous solution in the presence of ethylenediamine beta-CD dimer. The apparent association constant of the complex was 8.39 x 10(3) L mol(-1), and the linear range was 10.8-1.40 x 10(4) ng mL(-1) with the detection limit 3.2 ng mL(-1). There was no interference from the excipients normally used in tablets and serum constituents. The proposed method was successfully applied to the determination of tranilast in serum.