Abstract
Medicinal carbon (MC) granules were prepared by the wet granulation method (wet mass extrusion) using carboxymethylcellulose sodium (CMC-Na) as a binding agent. In addition, croscarmellose sodium (CC-Na) was used as an additive at 0 - 10% (w/w) to MC. The obtained granules were examined in vitro for the physical strength, disintegration properties and adsorption characteristics. From friability tests, all the granules had good strength. They slightly disintegrated in the disintegration test with water for 30 min, but the addition of CC-Na significantly reduced the granule weight after the disintegration test. It was suggested that the addition of CC-Na should facilitate water immersion and consequently cause components such as CMC-Na or CC-Na to be lost partially; though such changes in the physical state could not be discernible to the naked eye. In adsorption experiments using acetaminophen solution (0.6 mg/mL), the adsorption capacity was almost retained in all the granules. Although the adsorption rate of the granules without CC-Na was fairly slower than that of MC powder, it was significantly improved by the addition of the CC-Na at 4 and 10% (w/w). In particular, the granules with CC-Na at 10% (w/w) displayed 65% (w/w) of saturated adsorption with a small coefficient of variance (<7%) at 20 min after the start of the adsorption test. Thus, since the MC granules with CC-Na at 10% displayed good physical strength, high adsorption capacity and a fairly fast adsorption rate, they are suggested to be useful as a compact MC dosage form.
