Dissolution Advantage of Nitazoxanide Cocrystals in the Presence of Cellulosic Polymers

Salas-Zúñiga, Reynaldo; Rodríguez-Ruiz, Christian; Höpfl, Herbert; Morales-Rojas, Hugo; Sánchez-Guadarrama, Obdulia; Rodríguez-Cuamatzi, Patricia; Herrera-Ruiz, Dea

For the dissolution experiments employing the USP 1 apparatus, the powder formulations shown in Table 1 were added to a volume of 600 mL of pH 7.5 PBS solution, with a rotation speed of 100 rpm at 37 ± 0.5 • C. Samples of 4 mL were taken at 2, 5, 10, 15, 30, 60, 120 and 180 min, and an equal volume of fresh medium was added to maintain the dissolution medium volume constant. The NTZ concentration was quantified by UV-vis spectrophotometry at 435 nm ( Figures S2 and S3 ). Each dissolution profile represents the average of three experiments. After the dissolution experiments, the solid residues were collected and dried at room temperature for analysis by PXRD and by scanning electron microscopy (SEM). Finally, a test comparing a powder formulation with Methocel ® 60 HG Pharmaceutics 2020, 12, 23 5 of 18 5% w/w containing 500 mg of NTZ as NTZ-SUC cocrystal and a commercially available formulation (500 mg tablet) was performed. The reference tablets of NTZ (Daxon ® , 500 mg NTZ) were ground in an agate mortar and passed through a sieve mesh 200. All the dissolution profiles are presented as mg of NTZ dissolved vs. time. The mg of NTZ dissolved was calculated as: