Simultaneous Determination of Acetaminophen (Paracetamol) and Ascorbic Acid in Pharmaceutical Formulations by LC Coupled to a Screen Printed Carbon Based Amperometric Detector

Abstract

The assay of acetaminophen (APAP) and ascorbic acid (AA) was performed by liquid chromatography (LC) with amperometric detection at a screen printed carbon based electrode poised at + 0.6 V versus Ag pseudoreference electrode. A microparticle based conventional RP-C18 and a monolithic RP-C18 column were studied comparatively for the analytes separation using a mobile phase based on 0. 1 M phosphate buffer-methanol 91 : 9 (v/v) at pH 6.5. The linear calibration range for both compounds was comprised within 2 10 À7 -1 10 À4 M. Limit of detection (LOD) for APAP and AA was 2 10 À7 and 5 10 À7 M, respectively and the limit of quantification (LOQ) was 5. 10 À7 and 1 10 À6 M, respectively. Square wave voltammetry at a Nafion modified glassy carbon electrode was developed and applied to the determination of APAP in order to validate the results obtained by the monolithic LC method for drug formulations.

Utility of Screen Printed Electrodes for in Vitro Metabolic Stability Assays: Application to Acetaminophen and its Thioconjugates

“…The APAP electrooxidation data fit well with former and new literature data on APAP in vivo metabolism [35]. It can safely been stated that electrochemical synthesis using screen printed electrodes, in addition to useful mechanistic and quantitative data [28,29], may be of valuable predictive value for the investigation of the metabolic profile of electroactive drug compounds. The development of screen printed electrodes possessing a working electrode with extended potential domain will allow the study of a broader spectrum of drug compounds and reaction mechanisms.…”

“…The acetaminophen (APAP) electrooxidation pattern has been quite extensively studied by electrochemical [21,22] and enzymatic methods [23][24][25][26] and therefore APAP is of particular utility in method development. APAP has already been studied by cyclic voltammetry and amperometry at screen printed carbon electrodes for mechanistic and quantitative purposes [27][28][29] and enzyme modified CSPEs were also described for the assay of APAP [30]. APAP is a very popular analgesic and antipyretic drug, it is non carcinogenic and an effective substitute of aspirin for patients who cannot tolerate aspirin [31].…”

Screen-Printed Electrodes (SPE) for Drug Compounds Determination

“…Sarakbi et al have developed a rapid and sensitive method for simultaneous quantification of these two components by LC using a monolithic column coupled to a SWCNT-based SPE housed in a wall-jet flow cell configuration. The linear calibration range for both compounds was comprised between 2.10 À7 -1.10 À4 M. Limit of detection (LOD) for APAP and AA was 2.10 À7 and 5.10 À7 M, respectively, and the limit of quantification (LOQ) was 5.10 À7 and 1.10 À6 M [70]. Graphene is a carbon allotrope that has a two-dimensional honeycomb lattice structure.…”

Electrochemical and Hyphenated Electrochemical Detectors in Liquid Chromatography and Flow Injection Systems for Drug Compound Analysis

“…All these criteria are of prime importance in routine analytical laboratories in the pharmaceutical industry. The suitability of a carbon-based SPE as amperometric detector for FIA [50] and LC [51] was illustrated for the assay of paracetamol in drug formulations. [1,52] …”