Comparative evaluation of ammonium chloride-modified and hospital-grade activated charcoal for paracetamol adsorption under simulated gastric (pepsin) and intestinal (pancreatin) fluid.

INTRODUCTION: Paracetamol overdose is a major cause of drug-induced toxicity, and activated charcoal is routinely used for gastrointestinal decontamination. This study compares the adsorption efficiency of ammonium chloride-modified activated charcoal, synthesized from Calligonum comosum wood, with hospital-grade activated charcoal in simulated gastric and intestinal fluid.

METHODS: Adsorption experiments were conducted using 20 mg of activated charcoal, in a paracetamol solution containing 2.5 mg of paracetamol (50 mg/L in 50 mL), corresponding to an adsorbent-to-drug ratio of 8:1 at 37 °C. Simulated gastric and intestinal fluid were prepared using pepsin and pancreatin, respectively. For isotherm analysis, paracetamol solutions were tested at charcoal-to-drug ratios ranging from 1:1 to 10:1 using a fixed 20 mg adsorbent dose. Kinetic modeling and the effects of ethanol and flavoring agents were also evaluated.

RESULTS: Paracetamol adsorption efficiencies were 87 ± 0.5% and 85 ± 0.8% for modified activated charcoal in simulated gastric and intestinal fluid, respectively. Hospital-grade activated charcoal efficiencies were 47 ± 0.7% and 58 ± 0.6%. Maximum adsorption capacities were 574.93 and 566.71 mg/g for modified activated charcoal and 173.98 and 294.64 mg/g for hospital-grade activated charcoal. Adsorption data fitted the Freundlich isotherm for modified activated charcoal and the Langmuir model for hospital-grade activated charcoal. Exposure to ethanol reduced adsorption by approximately 14% and 32% for modified and hospital-grade activated charcoals, respectively. Flavoring agents reduced adsorption by about 5% and 10% for modified and hospital-grade activated charcoals, respectively. Kinetic analysis indicated a pseudo-second-order model for both materials.

DISCUSSION: Modified activated charcoal showed higher paracetamol adsorption efficiency and capacity than hospital-grade activated charcoal under simulated gastric and intestinal conditions, with stable performance in enzyme and flavoring agent environments.

CONCLUSION: These findings suggest modified activated charcoal may improve adsorption for gastrointestinal decontamination; however, comparative studies with multiple commercial medicinal charcoals and in vivo evaluation are needed to confirm clinical applicability.