Determination of Mexiletine in Pharmaceutical Preparations by Linear Sweep Voltammetry

A simple and rapid method for determination of mexiletine in pharmaceutical preparations was developed and validated using linear sweep voltammetry (LSV). The proposed method was based on electrochemical oxidation of mexiletine at platinum electrode in acetonitrile solution containing 0.1 M LiCIO4. The well-defined an oxidation peak was observed at +1.11 V. The calibration curve was linear for mexiletine at the concentration range of 5-70 μg/mL for LSV method. Intraand inter-day precision values for mexiletine were less than 2.73, and accuracy (relative error) was better than 3.89%. The mean recovery of mexiletine was 100.1% for pharmaceutical preparation. No interference was found excipient at the selected assay conditions. The method was found to be specific, precise and accurate. The method was applied for the quality control of commercial mexiletine capsule form to quantify the drug and to check the formulation content uniformity. INTRODUCTION: Arrhythmias, commonly observed as atrial fibrillation, atrial flutter, atrial tachycardia, ventricular tachycardia and premature beats, are the consequences of abnormal autorhythmicity or conduction disturbance of heart. Generally, antiarrhythic drugs therapy is preferred for patients with cardiac arrhythmia 1-3 . Mexiletine (Fig. 1), is an antiarrhythmic agent used in the treatment of ventricular arrhythmia 4 . It is available in the form of hydrochloride salt, a single dose ranges from 50-400 mg and a daily dose up to 1500 mg can be prescribed. The bioavailability of mexiletine is 80-90% by the oral route. Peak plasma concentration occurs 1-4 h after ingestion 5 . QUICK RESPONSE CODE DOI: 10.13040/IJPSR.0975-8232.IJP.2(7).335-41 Article can be accessed online on: www.ijpjournal.com DOI link: http://dx.doi.org/10.13040/IJPSR.0975-8232.IJP.2(7).335-41 FIG.1: CHEMICAL STRUCTURE OF MEXILETINE Several methods have been reported for determination of mexiletine including highperformance liquid chromatography (HPLC) 6-14 , LC-MS/MS 15 and gas chromatography-mass spectrophotometry (GC-MS) 16-18 in plasma and other biological fluids. The USPXXIII 19 describes a reverse phase HPLC method for its assay while the BP 93 20 describes a non aqueous titration method. The reported methods were influenced by interference of endogenous substances and potential loss of drugs in the re-extraction procedure and involving lengthy, tedious and timeconsuming plasma sample preparation and