A Third Phase Effect on the Phase Transition of Xylazine Hydrochloride

Initiation of phase transition was affected by the presence of hydrate H in the initial sample, but the presence of forms Z and M in the initial sample affected the middle interval of phase transition. The differences can be explained by accelerated nucleation of the stable polymorph A in the presence of water vapour released during the dehydration of hydrate H. However, in those cases when Z and M was added to the initial sample, the form X changed not only directly to A, but partially also to the polymorphs Z or M.