distillation decantation concentration or a combination thereof a fourth aspect of the present invention provides a method of determining the polymorphic form of palonosetron hydrochloride wherein the method comprises a generating an ftir spectrum of a sample of palonosetron hydrochloride and b determining the polymorphic form of said sample by the ratio of intensity of the peaks at about 1456 about 1446 and about 1408 cm u2212 1 the ftir spectrum of the sample of palonosetron hydrochloride may be generated by using potassium bromide pellet according the general test methods provided in the usp 25 page 1920 commercially available instruments for example perkin elmer spectrum one instrument may be used for the purposes the sample of palonosetron hydrochloride is determined as form i or as form ii by the ratio of intensity of the peaks at about 1456 about 1446 and about 1408 cm u2212 1 the ratio of the intensity of the peak at about 1446 cm u2212 1 to that of the peak at about 1408 cm u2212 1 is equal to or greater than about 0 32 in form i as depicted in fig8 of the accompanied drawing the ratio of the intensity of the peak at about 1446 cm u2212 1 to that of the peak at about 1408 cm u2212 1 is equal to or less than about 0 07 in form ii as depicted in fig8 of the accompanied drawing the ratio.