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A new polymorphic form of metoprolol succinate
Mengqing Zhou1, Ju Ao1, Song Liu1
1a Engineering Research Center for Eco-Dyeing and Finishing of Textiles, Ministry of Education, Zhejiang Sci-Tech University , Hangzhou , China and.
Pharmaceutical Development and Technology
|February 25, 2016
Summary
Researchers discovered a new crystal form of metoprolol succinate (Form II), which is metastable and dissolves faster in water than the previously known stable form (Form I). This finding impacts pharmaceutical development.
Area of Science:
- Pharmaceutical Science
- Solid-State Chemistry
- Crystallography
Background:
- Only one crystal form (Form I) of metoprolol succinate was previously documented.
- Metoprolol succinate is a widely used beta-blocker medication.
Purpose of the Study:
- To discover and characterize new polymorphic forms of metoprolol succinate.
- To investigate the properties and stability of the newly identified polymorph.
Main Methods:
- X-ray diffraction (XRD) for crystal structure analysis.
- Thermoanalysis (e.g., DSC, TGA) for thermal properties.
- Infrared (IR) spectroscopy for molecular structure.
- Dissolution testing to compare solubility.
Main Results:
- A new polymorph, metoprolol succinate Form II, was identified.
- Form II exhibits distinct XRD patterns, lower melting point, and weaker hydrogen bonding compared to Form I.
- Form II is a metastable form, transforming to Form I under elevated temperature and humidity.
- Form II demonstrated significantly enhanced dissolution rate in water compared to Form I.
Conclusions:
- Metoprolol succinate exists in at least two polymorphic forms (Form I and Form II).
- Form II, a metastable polymorph, offers potential advantages in drug formulation due to its improved solubility and dissolution rate.
- Understanding polymorphism is crucial for consistent drug performance and development.
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