A white to off white crystalline powder. Soluble in water and methanol, practically insoluble in acetone, chloroform, ethyl acetate. IR absorption spectrum of sample in KBR dispersion is concordant with that of reference standard of Tizanidine HCl. The retention time of the major peak in the chromatogram of the assay preparation corresponds to that in the chromatogram of the standard preparation, as obtained in the assay.