Effectiveness of commercially available aqueous activated charcoal products.

A human research project was conducted to compare the relative effectiveness of five commercially available aqueous activated charcoal products in 25-g amounts--Acta-Char, Actidose-Aqua, Insta-Char, Liqui-Char, and Super-Char. Seven healthy adult human fasting volunteers participated. The study was double-blinded and subjects served as their own controls. Aspirin 2,592 mg was administered to each subject in the control phase to establish baseline aspirin absorption as measured by serial serum salicylate levels. During each of the five study phases 2,592 mg aspirin and a specific brand of activated charcoal were administered to the subjects and serial serum salicylate levels were drawn. Aspirin absorption was calculated using the trapezoidal rule for measuring the area under the concentration-time curve. Total aspirin absorption was reduced as follows: Super-Char, 57.76%; Actidose-Aqua, 50.42%; Insta-Char, 39.55%; Liqui-Char, 33.40%; and Acta-Char, 27.46%. Although there were large apparent differences in the adsorptive capacities of the products, the only statistically significant difference was between Super-Char and Acta-Char. The failure to show statistical differences in the face of large apparent differences may have been a reflection of type II beta error due to the small sample size. The most common factor responsible for the apparent differences in the adsorptive capacities of the products was most likely the surface area of the activated charcoals that were used. The higher surface area products, Super-Char (3,150 m2/g) and Actidose-Aqua (1,500 m2/g) prevented the absorption of aspirin more effectively than the other three products that had surface areas of 950 m2/g.