Novel pharmaceutical cocrystal consisting of paracetamol and trimethylglycine, a new promising cocrystal former.

Paracetamol (APAP), a frequently used antipyretic drug, has poor compression moldability. In this study, we identified a novel cocrystal consisting of APAP and trimethylglycine (TMG) that exhibits improved tabletability. TMG was used instead of oxalic acid (OXA), which is a coformer reported previously. The cocrystal (APAP-TMG at a molar ratio of 1:1) was characterized by X-ray analysis, infrared spectroscopy, and thermal analysis. The crystal structure of APAP-TMG revealed that it was a cocrystal, since no proton was transferred between the APAP and TMG molecules. The compression and dissolution properties of APAP-TMG were similar to that of the APAP-OXA cocrystal. In addition, taste sensing measurements suggested that TMG has a sweet and umami taste, indicating that TMG should suppress the bitterness of APAP. From these results, TMG could be a safe and promising cocrystal former that could replace OXA, which can irritate tissues.