Comparative Study of Different Electrochemical Sensors for Potentiometric Determination of Mepivacaine Hydrochloride in Bulk Powder and in Pharmaceutical Preparation

Research Article

Austin J Anal Pharm Chem. 2018; 5(3): 1108.

Comparative Study of Different Electrochemical Sensors for Potentiometric Determination of Mepivacaine Hydrochloride in Bulk Powder and in Pharmaceutical Preparation

El-Abasawy NM, Attia KAM, Abo-Serie AA, Said RA and Almrasy AA*

Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Al-Azhar University, 11751, Nasr City, Cairo, Egypt

*Corresponding author: Ahmed A Almrasy, Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Al-Azhar University, 11751, Nasr City, Cairo, Egypt

Received: October 03, 2018; Accepted: November 02, 2018; Published: November 09, 2018

Abstract

Objective: Development and validation of three electrochemical sensors for determination of mepivacaine hydrochloride (MC) in its bulk powder and in pharmaceutical preparation.

Methods: The three electrochemical sensors based on the use of mepivacaine- reineckate (MC-RT) ion pair as an electroactive material in plasticized PVC membrane, carbon paste and coated graphite sensors.

Results: The suggested three-sensors show a near-Nernstian response for MC over a wide concentration range of 1×10-5-1×10-2 M with detection limits of 7.2x10-6, 7.4x10-6 and 7.5x10-6 M for PVC, coated graphite and carbon paste sensors. The proposed sensors have a fast response time and can be used for 2-4 weeks without any considerable divergence in potentials.

Conclusion: They exhibit comparatively good selectivity with respect to related substances, dosage form additives, alkaline earth and some heavy metal ions, the proposed sensors have been successfully applied for the determination of MC in its pharmaceutical formulation. Also, the obtained results have been statistically compared to a reported method indicating no significant difference between the investigated methods and the reported one with respect to accuracy and precision.

Keywords: Mepivacaine; Potentiometry; PVC; Coated graphite; Carbon paste

Introduction

Mepivacaine hydrochloride, (Figure 1), is (1-methyl-2-piperidyl) formo-2´, 6´-xylidide hydrochloride. Its molecular weight is 282.80 and its molecular formula is C15H23ClN2O. It is white or almost white crystalline powder. It is freely soluble in water and alcohol [1]. It is official in United States Pharmacopoeia which recommend a titration for determination of MC in pure form using 0.1N perchloric acid as a titrant and crystal violet as indicator [2]. Different analytical methods have been reported for the determination of mepivacaine including very few spectroflurometric [3], electrochemical [4], chromatographic [5-15] and capillary electrophoretic methods [16,17] in both clinical and experimental medicine.

The present work establishes simple, accurate, rapid and reproducible sensors for determination of MC. These sensors incorporate the ion association complexes of MC cation with ammonium reineckate as a counter anion in each composition of the proposed three sensors. These sensors have fast response and near-Nernstian slopes. The proposed sensors have been demonstrated to be superior to the reported methods with respect to speed, simplicity, sensitivity, selectivity and cost-effectiveness, and have been successfully applied for the determination of MC in simple and complex matrices.

Experimental

Instruments

Chemicals and solvents

All reagents used were of analytical grade and water used throughout the procedure was freshly distilled.