These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Crystallization behavior of mannitol in frozen aqueous solutions. Author: Cavatur RK, Vemuri NM, Pyne A, Chrzan Z, Toledo-Velasquez D, Suryanarayanan R. Journal: Pharm Res; 2002 Jun; 19(6):894-900. PubMed ID: 12134963. Abstract: PURPOSE: To study the effect of cooling rate, the influence of phosphate buffers and polyvinylpyrrolidone (PVP) on the crystallization behavior of mannitol in frozen aqueous solutions. METHODS: Low-temperature differential scanning calorimetry and powder X-ray diffractometry were used to characterize the frozen solutions. RESULTS: Rapid cooling (20 degrees C/min) inhibited mannitol crystallization, whereas at slower cooling rates (10 degrees C and 5 degrees C/min) partial crystallization was observed. The amorphous freeze-concentrate was characterized by two glass transitions at -32 degrees C and -25 degrees C. When the frozen solutions were heated past the two glass transition temperatures, the solute crystallized as mannitol hydrate. An increase in the concentration of PVP increased the induction time for the crystallization of mannitol hydrate. At concentrations of > or =100 mM, the buffer salts significantly inhibited mannitol crystallization. CONCLUSIONS: The crystallization behavior of mannitol in frozen solutions was influenced by the cooling rate and the presence of phosphate buffers and PVP.[Abstract] [Full Text] [Related] [New Search]