A monoclinic polymorph of chloro-thia-zide

Area of Science:

• Crystallography
• Solid-state chemistry
• Pharmaceutical science

Background:

• Chloro-thia-zide is a diuretic drug.
• Polymorphism, the existence of different crystal forms, can affect drug properties.
• Understanding crystal structures is crucial for drug development.

Purpose of the Study:

• To describe a newly identified polymorph of chloro-thia-zide.
• To compare the thermodynamic stability and intermolecular interactions of the new polymorph with the known form.

Main Methods:

• Crystallization from a basic aqueous solution.
• X-ray diffraction analysis to determine crystal structure.
• Thermodynamic analysis and hydrogen bond characterization.

Main Results:

• A new monoclinic polymorph of 6-chloro-1,1-dioxo-2H-1,2,4-benzo-thia-zine-7-sulfonamide was successfully crystallized.
• The monoclinic polymorph is less thermodynamically favored than the known triclinic (P1) polymorph.
• The monoclinic form exhibits only N-H⋯O hydrogen bonds, while the triclinic form shows both N-H⋯O and N-H⋯N interactions.

Conclusions:

• The discovery of a new polymorph expands the understanding of chloro-thia-zide's solid-state behavior.
• Differences in crystal packing and hydrogen bonding suggest potential impacts on physicochemical properties.
• Further studies are warranted to evaluate the implications of this new polymorph on drug formulation and efficacy.