Structure based release kinetics analysis of doxazosin mesylate sustained-release tablets using micro-computed tomography

The structures of solid dosage forms determine their release behaviors and are critical attributes for the design and evaluation of the solid dosage forms. Here, the 3D structures of doxazosin mesylate sustained-release tablets were parallelly assessed by micro-computed tomography (micro-CT). There were no significant differences observed in the release profiles between the RLD and the generic formulation in the conventional dissolution, but the generic preparation released slightly faster in media with ethanol during an alcohol-induced dose-dumping test. With their 3D structures obtained via micro-CT determination, the unique release behaviors of both RLD and the generic were investigated to reveal the effects of internal fine structure on the release kinetics. The structural parameters for both preparations were similar in conventional dissolution test, while the dissolutions in ethanol media showed some distinctions between RLD and generic preparations due to their static and dynamic structures. Furthermore, the findings revealed that the presence of ethanol accelerated dissolution and induced changes in internal structure of both RLD and generic preparations. Moreover, structure parameters like volume and area of outer contour, remaining solid volume and cavity volume were not equivalent between the two formulations in 40 % ethanol. In conclusion, the structure data obtained from this study provided valuable insights into the diverse release behaviors observed in various modified-release formulations in drug development and quality control.