Adjunctive Multicomponent Crystals of Two Anti-Tubercular Drugs with Pyridoxine

Background/Objectives: Cocrystallisation is a well-established path for altering the physicochemical properties and bioavailability of active pharmaceutical ingredients (APIs). A common side effect of anti-tubercular medicines is the depletion of group B vitamin reserves in TB patients. Co-administration of supplements such as pyridoxine (vitamin B₆) during TB therapy may be used to ameliorate the harmful side effects of vitamin B₆ deficiency. Methods: Mechanochemical grinding and solvent evaporation experiments using pyridoxine (PN) with 4-aminosalicylic acid (PAS) and separately with pyrazinecarboxylic acid (PCBA) were conducted. The bulk powder and crystal analysis was performed using FTIR, PXRD, DSC, TGA and SCXRD. Results: The isolation and characterization of two multicomponent salts containing pyridoxine, i.e., PN-PAS·H₂O and PN-PCBA, were completed. Mechanochemistry is an efficient method for the preparation of cocrystals. Conclusions: The drug-vitamin combinations may be useful for the development of new treatment regimens with potentially improved therapeutic outcomes and reduced adverse effects.