A lyophilized surfactant-based rutin formulation with improved physical characteristics and dissolution for oral delivery

Rutin (RUT) is a phytochemical flavonoid with numerous therapeutic potentials including antihypertension, cardioprotective, neuroprotective, and anti-cancer activities. Its clinical use is inhibited due to its poor aqueous solubility and permeability over oral administration. The present study aimed to overcome these problems through micellization and entrapment of RUT in solid dispersion (SD) using Poloxamer (POL) 407 and 188 as surfactant-based matrices. The RUT/SD formulations were prepared in serial drug loading concentrations in weight percentage to the total solid. The physical properties of the formed RUT/SD solids were characterized by several methods including polarizing microscopy, differential thermal analysis (DTA), X-ray diffractometry (XRD), scanning electron microscopy (SEM) and dissolution study. The dissolution test was performed using a paddle dissolution apparatus and samples were analyzed using UV spectrophotometry. Polarized microscope confirmed that the optical behaviors of the RUT/SD implied a formation of miscible RUT with POL matrices. The morphology of RUT/SDs varied from porous matrices with craters to smoother surfaces as a function of RUT concentrations. XRD and DTA data exhibited that RUT existed as partially amorphous. These data indicated that the higher concentration of RUT in the RUT/SD formulations, the higher amorphous proportion of the RUT in the solid state. Henceforth, this led to an increase in the percentage of dissolved RUT from the developed RUT/SD formulations at 94 to 100% compared to pure RUT at only < 35% within an hour. The present study disclosed the successful improvements in the physical characteristics of the RUT/SD formulations and their potencies for the future development for oral formulation.