Multicomponent Adducts of Pyridoxine: An Evaluation of the Formation of Eutectics and Molecular Salts

Cocrystallization of pyridoxine (vitamin
B6) with several
biologically important molecules was undertaken with the intent of
successfully designing various hydrogen bonded adducts such as salts,
cocrystals, and eutectics. Pyridoxine formed eutectics with isoniazid
(an antitubercular drug) and nicotinic acid (vitamin B3) and molecular
salts with para-aminobenzoic acid (a bioactive) and saccharin (an
artificial sweetener), respectively, in accordance to our design strategy.
A salt cocrystal, a precisely conjugate acid–base cocrystal,
was obtained for the pyridoxine–para-nitrobenzoic acid combination.
The role of supramolecular affinity of hydrogen bonding functional
groups and ΔpKa differences’
leading to the formation of above diverse adducts was discussed. This
study underpins the need for full-fledged supramolecular compatibility
studies of multivitamin/drug combinations toward the development of
optimal and/or synergistic combination formulations.