New pharmaceutical salts containing pyridoxine

Area of Science:

• Crystallography
• Pharmaceutical Science
• Supramolecular Chemistry

Background:

• Pyridoxine (PN), a vital B6 vitamin, is an active pharmaceutical ingredient.
• Co-crystallization is a strategy to improve drug properties.
• Ferulic acid and syringic acid are phenolic compounds with known bioactivities.

Purpose of the Study:

• To synthesize and characterize novel pharmaceutical salts of pyridoxine with ferulic acid and syringic acid.
• To investigate the crystal structures and intermolecular interactions of these new salts.
• To understand the role of pKa differences and bonding in salt formation.

Main Methods:

• Crystallization of pyridoxine with ferulic acid and syringic acid.
• Single-crystal X-ray diffraction for structural analysis.
• Hirshfeld surface analysis to quantify intermolecular interactions.

Main Results:

• Two 1:1 pyridoxine-coformer pharmaceutical salts were successfully obtained: pyridoxine-ferulate and pyridoxine-syringate monohydrate.
• Proton transfer from the coformer to pyridoxine occurred, forming salts.
• Complex hydrogen-bonding networks and π-π interactions were identified as key to crystal packing.

Conclusions:

• The formation of pyridoxine pharmaceutical salts with ferulic acid and syringic acid is feasible and results in stable crystalline structures.
• Intermolecular interactions, including hydrogen bonding and π-π stacking, play a crucial role in the crystal architecture of these salts.
• Hirshfeld analysis provides detailed insights into the nature and contribution of various intermolecular forces.