Comparison on the adsorptive capacity of Fuller's earth, Actidose Aqua(R) and activated charcoal

ABSTRACT

BACKGROUND: Activated charcoal has been widely used as an adsorbent for the management of drug intoxicated patients in the emergency department(ED). Although there are several commercial ready-mixed charcoal suspension preparations in the market, we are using custom-made suspension from hospital grade bulk charcoal powder. We designed this study to compare the adsorptive capacity of the Actidose Aqua(R), which is a commercial charcoal product, Fuller's earth, and custom-made activated charcoal used in our ED. METHODS: First, we performed modified USP methylene blue adsorption test which is a standard adsorption test for activated charcoal. Then, the drug adsorption test for phenobarbital, acetaminophen, salicylate, and aminophylline was done. Graded amount of three adsorptives were added to the stock solutions of each drugs. The adsorption test were performed as follows The vials containing drugs and adsorptives were shaken for 30 minutes to ensure adsorption equilibrium, then the suspension was filtered through in-line filter. The filtrates were analyzed by ultraviolet spectroscopy to determine the residual drug concentrations. Finally we examined and compared the surface area and the structure of activated charcoal and Fuller's earth using scanning electron microscopy. RESULTS: In methylene blue adsorption test, the adsorption rate was 60.1% in Actidose Aqua(R) and 59.0% in custom-made charcoal, and 70.2% in Fuller's earth. For the phenobarbital, acetaminophen, and sallcylate, the adsorption rate of Actidose Aqua(R) and custom-made charcoal was greater than 90% with the ratio o adsorptives to drugs over 101. For aminophylline, two charcoal products showed excellent adsorption in 51 ratio. But Fuller's earth showed poor adsorption in all rages. CONCLUSION: Custom-made activated charcoal showed a comparable adsorption capacity to Actidose Aqua(R). Fuller's earth showed a poor performance to be used as a substitute for activated charcoal in acute drug poisoning otherwise paraquat.