Xanthan gum-based food thickeners have been reported to potentially interfere with tablet disintegration. Loxoprofen sodium (LOX) is widely used as an antipyretic analgesic and is expected to provide rapid pain relief. In this study, we aimed to investigate the impact of a xanthan gum-based food thickener on LOX tablet disintegration. We used four different brands each of medical and OTC-LOX tablets, each containing 60 mg of LOX as the sole active ingredient. Depending on the brand, tablet hardness varied between 50.1–96.6 N and was not associated with the disintegration time. Disintegration times for medical tablets not immersed in the food thickener were 536±215, 621±159, 348±22, 369±42 s and for OTC tablets, were 358±20, 336±13, 292±13, 172±27 s. Immersion in the food thickener for 15 min reduced medical tablet disintegration time to 177±46 and 233±150 s (the third and fourth brands were disintegrated during immersion), and that for OTC tablets to 77±40, 75±110, and 37±85 s (the fourth brand was disintegrated during immersion). Despite each tablet containing different pharmaceutical additives, no correlation was found between disintegration time and presence of superdisintegrants. The OTC tablet with a light anhydrous silicic acid coating exhibited the shortest disintegration time. Thus, the disintegration time of LOX tablets is accelerated when immersed in the xanthan gum-based food thickener, potentially leading to rapid pain relief for patients.