[Xanthan Gum-based Food Thickeners Reduce Disintegration Time of Medical and OTC Loxoprofen Sodium Tablets]

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.

Fabrication and in vitro characterization of HPMC-g-poly(AMPS) hydrogels loaded with loxoprofen sodium

The aim of this study was to prepare hydroxypropyl-methyl cellulose (HPMC)-K15 based hydrogels via free radical polymerization using 2‑acrylamido-2‑methyl propane sulphonic acid (AMPS) as a monomer and N,N'-methylene bisacrylamide (MBAAm) as a crosslinker. Loxoprofen sodium was chosen as a model drug and successfully loaded in hydrogel discs. Sol-gel, porosity, loading efficiency, and the in vitro drug release analysis were carried out to evaluate its drug delivery potential. HMPC-g-poly(AMPS) hydrogels were characterized by using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) approaches. Maximum swelling and drug release were observed at pH 7.4. Kinetic modelling suggested that drug release followed first-order kinetics with the non-Fickian mechanism. FTIR and DSC confirmed the formation of new hydrogels. SEM micrographs confirmed uneven, rough, and partially porous type of surface. These results suggested that HMPC-g-poly(AMPS) hydrogels can be a prospective pH-responsive carrier for delivery of water-soluble drugs, such as loxoprofen sodium.