Novel naproxenate screen-printed potentiometric sensors

Background and objectives Naproxen (S)-6-methoxy-alpha-methyl-2-naphthaleneacetic acid (or sodium salt) belongs to a group of pharmaceuticals known as NSAIDs. The aim of this study is to describe the construction and performance characteristics of naproxen (NAP) screen-printed sensors. Materials and methods Various sensor fabrication protocols have been applied including bulk modification with NAP-surfactants ion pairs (IPs), in-situ modification with ion pairing agents and soaking the plain electrode in IP suspension solutions. Qualitative and quantitative matrix composition optimization was done referring to the effect of modifier and plasticizer. Conductometric measurements were performed for the determination of the solubility products of NAP-surfactants ion associates. Results and conclusion The fabricated sensors showed Nernstian compliance in the concentration range from 10(-7) to 10(-2) mol/l (detection limit 8.0x10(-8) mol/l) with fast response time (4 s) and long operational lifetime (3 months). The developed electrodes have been successfully applied for the potentiometric determination of NAP in pure and dosage forms under standard addition and potentiometric titration conditions with average recoveries agreeable with the reported official methods. The solubility products of various NAP-IPs were determined conductometrically.