MCM-41 for Meloxicam Dissolution Improvement:in vitroRelease andin vivoBioavailability Studies

Abstract

In this study, MCM-41 was prepared as a carrier for poorly water soluble drugs. Meloxicam (MLX) was selected as model compound. Textural and chemical characterizations were carried out by thermal gravimetric analysis (TGA), scanning electron microscope (SEM), nitrogen adsorption/desorption, X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The in vitro release of MLX was performed at pH 1.2 and 6.8. After loading MLX into MCM-41, its oral bioavailability was compared with the free drug and the marketed product Mobic® (R) in rabbits. After administration of free MLX to rabbits (5 mg kg–1), MLX presented a two distinct double-peak profile in case of R and F2 due to enterohepatic cycling. The effect of MCM-41 was mainly on the rate not the extent of MLX absorption. Administration of free MLX to rabbits resulted in an AUC0–∞ value of 11.9 µg h mL–1 and a Tmax of 4.3 h. When the same dose of MLX was introduced as R or formulated into MCM-41 (F2; MLX to MCM-41 ratio of 0.7), the systemic exposure to MLX was raised significantly by ca. 4-fold as reflected in AUC0–∞ value of 46.9 and 45.5 µg h mL–1 for R and F2, respectively. Development of an immediate formulation could enhance the curative effect of MLX by increasing its drug release and dissolution rate in the preferential absorptive region.