Medicinal carbon tablets for treatment of acetaminophen intoxication: adsorption characteristics of medicinal carbon powder and its tablets

Adsorption characteristics of medicinal carbon powder (JP 14) for acetaminophen were examined at 37 degrees C using conventional incubation in an attempt to obtain an effective oral dosage form. Hydroxypropyl cellulose (HPC) and maltitol (MT), being able to act as a binding agent, were tested as additives. Tablets of medicinal carbon were produced by the wet granulation method. The rate and extent of adsorption of the medicinal carbon powder were roughly similar in water, JP 14 1st fluid (pH 1.2) and JP 14 2nd fluid (pH 6.8). The relationship between concentrations of free and adsorbed acetaminophen indicated that the adsorption followed the Langmuir mode. The maximal adsorption of acetaminophen in water was 0.219 g per gram medicinal carbon powder, little influenced by the addition of MT, but slightly reduced by the addition of HPC. The tablet prepared using MT as a binding agent displayed a favorable hardness and adequate disintegration time. The tablet showed good adsorption potential for acetaminophen, though the adsorption rate and extent of the tablet were reduced to some extent as compared with powder.