This study verified the usefulness of additives for the stabilization of dissolved material in the liquid stage as in the case of crystallization. Additives were introduced to prevent dissolved crystals from isomerization and degradation. The case study here is astaxanthin, a carotenoid occurring in different isomers. The molecule structure is susceptible to a plethora of substances and factors which cause transformation and degradation of the isomers. The aim was to examine whether foreign materials (additives) would induce a change of the kinetics of a system consisting of crystalline all-trans astaxanthin dissolved in chloroform. The results show that K2CO3 and CH3COOK increase the stability of all-trans astaxanthin in solution.