The synergistic effect of zeolites and polyethylene glycol for the determination of the anti-epileptic drug eslicarbazepine acetate and its metabolite

•Determination of ESL using zeolites and PEG in the drug formulation water and urine samples.•Electrocatalytic properties with wide linear range and no interference by AA or the co-administered drugs.•The background does not cause any significant effects on the LOD and LOQ values. A novel and advanced sensor was fabricated by combining the intrinsic properties of the carbon paste electrode (CPE) with the naturally occurring zeolites (ZEO) and the nontoxic, hydrophilic polyethylene glycol (PEG) to form CPE/ZEO/PEG for the electrochemical determination of Eslicarbazepine acetate (ESL); a new central nervous system (CNS) pro-drug used for the treatment of epilepsy. Several techniques were used in this study to characterize CPE/ZEO/PEG, investigate ESL oxidation mechanism and to prove the formation of ESL metabolite base (eslicarbazepine base ((S)-licarbazepine). The results show that the surface modification improved the electroactive surface area and absorptivity that displayed a remarkable increase in the oxidation peak current of ESL acetate and ESL base (in urine samples). Experimental results specify a linear relation between ESL peak current and its concentration without interference either by AA or by its co-administered drugs gabapentin (GB) and levetiracetam (LV) giving 6.76 × 10−9 mol L-1 and 2.25 × 10 -8 mol L-1 for LOD and LOQ respectively Finally, CPE/ZEO/PEG sensor was effectively used to determine Eslizeb tablets with satisfactory recoveries.