Fabrication and characterization of disposable stencil printed ion selective electrode with improved sensitivity for determination of antiallergic epinastine HCl in opthalmic solution

Recently, a great attention is focused on developing and utilizing solid state electrochemical sensors in performing analytical applications at low cost. Herein, we report the fabrication and characterization of a disposable potentiometric ion selective strip with improved detection limit for determination of epinastine HCl (EP) in ophthalmic solution. Several ion-exchangers including epinastine-tetraphenyl borate (EP-TPB), epinastine-silicotungestate (EP-SiTA) and potassium tetrakis (4-chlorophenyl) borate (KTCPB) in presence of different plasticizers were investigated. However, an optimal potentiometric response with a Nernstian slope of 59 ± 0.5 mV/decade (n = 3) over a wide concentration range (1 × 10 −5 –1 × 10 −2 M, r = 0.9998), with a detection limit of 3.7 × 10 −6 M was achieved with KTCPB as a lipophilic cation exchanger. Furthermore, the current reverse chronopotentiometric (CRC) measurement showed a high potential stability of printed carbon electrode compared to a coated glassy carbon as inner solid contact. The present method is validated for the assay of epinastine with high accuracy and precision.