The present disclosure relates to a phase change material (PCM) composition and a process for preparation thereof, wherein said composition comprising a phase change material, glass fibers and xanthan gum. In a preferred embodiment, the phase change material is water (or ice) and the g lass fibers are glass wool. The disclosure also relates to a stackable and sealable package enclosing the PCM composition. In a particular embodiment, the PCM composition is used to prepare a cold box that may be used in cold chain transportation.