Investigation of the Physicochemical Properties of Medicine in the Ground Tablets and the Evaluation for Dispensing Characteristics of Ground Tablets.

The effect of grinding of the carbamazepine (CBZ) tablets (Tegretol® tablet; Teg-tab.) on the physicochemical properties of carbamazepine was investigated using X-ray diffraction, differential scanning calorimetric and fourier transform infrared spectrophotometric measurements. The ground samples were prepared by grinding Teg-tab. using an electrical tablet grinder or an agate mortar and pestle. There were no changes in the crystallinity of CBZ before and after grinding. In the infrared spectra of the ground sample prepared by the electrical tablet grinder, a peak shift suggesting a molecular interaction between CBZ and its excipients were observed. The dissolution rates of CBZ from the ground samples prepared by using an electrical tablet grinder were faster than those of Tegretol® fine granules or the ground samples prepared using the agate mortar and pestle. According to the measurements of the mean diameters of the ground samples, the differences in the dissolution behavior of the ground samples were due to the mean diameter of the ground samples, namely, the smaller the mean diameter by the elongation of the grinding time, the faster the CBZ dissolved. Furthermore, the dispensing characteristics of the ground samples were evaluated. As a result, the dispensing characteristics of the ground samples were observed to possibly greatly depend upon the micromeritical properties of the ground samples, such as the bulk density, compressibility and uniformity.