Adsorption of Voltaren on porous carbon materials under static and dynamic conditions

Abstract

The article investigates the adsorption of diclofenac (pure API and as part of the Voltaren preparation) on porous carbon materials obtained from rice husks by chemical activation methods (H₃PO₄, K₂CO₃, KOH), as well as on synthetic carbon from xerogel. A comparative assessment of the sorption capacity and the kinetics of the process was carried out under static and dynamic conditions. It was found that the KOH-activated sample (S_BET = 2610 m²/g) has the highest microporosity and demonstrates the maximum adsorption capacity (up to 956 mg/g in static and up to 1016 mg/g in a column with a fixed layer). Kinetic data is well described by a pseudo second-order model (R² > 0.99), and dynamic adsorption is described by the Thomas model (R² = 0.998). This allows us to predict the efficiency of sorbents in flow systems. There was no significant effect of the auxiliary components of the dosage form on the sorption process. The established patterns indicate the predominant interaction of the diclofenac molecule with the microporous carbon matrix through π–π interactions and electrostatic effects. The results obtained confirm the prospects of alkaline-activated carbon materials based on biomass for the development of effective enterosorbents for intoxication with nonsteroidal anti-inflammatory drugs.