Dual fluorescence of dothiepin, doxepin drugs-effect of solvents and β-cyclodextrin

► We investigate the spectral characteristics of dothiepin and doxepin drugs. ► In all solvents dothiepin maximum is red shifted than doxepin. ► The inclusion complexes were analyzed by UV-Visible and fluorometric methods. ► We calculated the stoichiometry and binding constant of the inclusion complex. ► The dothiepin and doxepin drugs form 1:3 inclusion complexes with β-cyclodextrin.