Evaluation of Correlation between Dissolution Rates of LoxoprofenTablets and Their Surface Morphology Observed by Scanning ElectronMicroscope and Atomic Force Microscope

摘要

We observed the surface morphological structures of 60 mg tablets of Loxonin, Loxot, and Lobu usingscanning electron microscope (SEM) and atomic force microscope (AFM) to evaluate the dissolution rates. Wefound a significant difference among the initial dissolution rates of the three kinds of loxoprofen sodium tablets.Petal forms of different sizes were commonly observed on the surface of the Loxonin and Loxot tablets inwhich loxoprofen sodium was confirmed by measuring the energy-dispersible X-ray (EDX) spectrum of NaKausing SEM. However, a petal form was not observed on the surface of the Lobu tablet, indicating differencesamong the drug production processes. Surface area and particle size of the principal ingredient in tablets are im-portant factors for dissolution rate. The mean size of the smallest fine particles constituting each tablet was alsodetermined with AFM. There was a correlation between the initial dissolution rate and the mean size of thesmallest particles in each tablet. Visualizing tablet surface morphology using SEM and AFM provides informa-tion on the drug production processes and initial dissolution rate, and is associated with the time course of phar-macological activities after tablet administration.