Multicomponent pharmaceutical cocrystals: furosemide and pentoxifylline.

Area of Science:

• Crystallography
• Pharmaceutical Science
• Supramolecular Chemistry

Background:

• Furosemide and pentoxifylline are active pharmaceutical ingredients with distinct chemical structures.
• Cocrystal formation is a strategy to modify the physicochemical properties of drugs.
• Understanding intermolecular interactions is crucial for drug design and formulation.

Purpose of the Study:

• To investigate the cocrystallization of furosemide and pentoxifylline.
• To characterize the resulting cocrystal, cocrystal hydrate, and cocrystal acetone solvate.
• To analyze the hydrogen bonding patterns and structural features of these new solid forms.

Main Methods:

• Single-crystal X-ray diffraction was used to determine the structures of the cocrystals.
• Analysis of hydrogen bond donors and acceptors.
• Calculation of packing indexes to assess crystal lattice efficiency.

Main Results:

• Three distinct 1:1 cocrystal forms were successfully synthesized and characterized: a cocrystal, a cocrystal hydrate, and a cocrystal acetone solvate.
• A rarely observed synthon with graph set R(2)(2)(7) was identified in the crystal structures.
• Detailed analysis revealed the participation of furosemide's hydrogen bond donors and varying engagement of its acceptors, alongside pentoxifylline's hydrogen bond acceptors, correlating with packing efficiencies.

Conclusions:

• The study successfully produced and characterized novel furosemide-pentoxifylline cocrystals, hydrate, and solvate.
• The identified hydrogen bonding patterns and synthons provide insights into the supramolecular assembly of these drug molecules.
• The findings contribute to the understanding of cocrystal engineering for pharmaceutical applications.