The aim of this study is to compare the dissolution time of six formulations of paranteralSodium Ceftriaxonepreparation, the original product and five generic local ones. The dissolution time was measured precisely as the point at which the dried powder of Sodium Ceftriaxone preparation became a transparent solution on the addition of physiologicalsolution 0,9% of Sodium Chloride. The dissolution time of the six products were different. The measurement of infrared spectroscopy (FTIR) of different powder preparations was conducted, then the weight, the humidity and the morphology of different medical powders were studied to investigate the factors influencing the dissolution time. The difference in dissolution time between the six products was due to differences in powder characteristics such as water content, crystal shape and dimension. It was shown that one local generic product of Sodium Ceftriaxone islook like the original one.