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.