Related Experiment Videos
Crystallization of D-mannitol in binary mixtures with NaCl: phase diagram and polymorphism
Chitra Telang1, Raj Suryanarayanan, Lian Yu
1College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA.
Pharmaceutical Research
|January 17, 2004
Summary
Sodium chloride (NaCl) and D-mannitol show significant melt miscibility, forming a eutectic phase diagram. NaCl influences D-mannitol
Area of Science:
- Physical Chemistry
- Materials Science
- Crystallography
Background:
- Understanding the interactions of excipients like D-mannitol and salts in pharmaceutical formulations is crucial for stability.
- Polymorphism of D-mannitol can impact its physical properties and performance in frozen aqueous solutions.
Purpose of the Study:
- To investigate the crystallization, polymorphism, and phase behavior of D-mannitol in binary mixtures with sodium chloride (NaCl).
- To elucidate the interactions between D-mannitol and NaCl in frozen aqueous solutions.
Main Methods:
- Differential scanning calorimetry (DSC)
- Hot-stage microscopy (HSM)
- Raman microscopy
- Variable-temperature X-ray diffractometry (VT-XRD)
Main Results:
- D-mannitol and NaCl exhibit significant melt miscibility up to 7.5% w/w NaCl, forming a eutectic phase diagram.
- NaCl influences the polymorphic crystallization of D-mannitol, with sample size affecting the resulting polymorph (delta or alpha).
- KCl shows similar behavior to NaCl, while LiCl inhibits crystallization and allows observation of D-mannitol's glass transition.
Conclusions:
- Despite structural differences, D-mannitol and NaCl display substantial melt miscibility and a defined phase diagram with polymorph-dependent eutectic points.
- NaCl impacts D-mannitol's polymorphic behavior through a two-stage crystallization process.
- The findings are relevant for formulating and stabilizing D-mannitol in frozen aqueous systems.