VIOREL-PUIU PAUN, CRISTINA MARCELA RUSU, MARICEL AGOP SOLVENT INFLUENCE ON THE ELECTRONIC ABSORPTION SPECTRA OF B3 VITAMIN IN TERNARY SOLUTIONS The spectral shifts in the visible electronic absorption spectra of B3 in water-ethanol mixtures were correlated with the macroscopic parameters (refractive index and electric permittivity) of the solvents. The contributions of the intermolecular interactions upon the spectral shifts as a function of the solvent macroscopic parameters were expressed by multiparameter regressions. The dependence of the wave number in maximum vibronic band of B3 vitamin on the solvent macroscopic parameters demonstrates the prelevance of the orientation interactions in the studied solutions. Some electro-optical parameters and global descriptors of B3 vitamin were computed by Spartan program. In present, the assimilation of the B3 vitamin copolymeric compounds in medicine and cosmetics must fullfil the complexity of the biological issues that result from using them. We note that the B3 vitamin can be incorporated in the polymeric structures to improve its functions.