INTERNATIONAL JOURNAL OF BIOASSAYS ISSN: 2278-778X CODEN: IJBNHY ORIGINAL RESEARCH ARTICLE OPEN ACCESS *Corresponding Author: Mr. N.Y. Sreedhar, Electroanalytical Lab, Department of Chemistry, Sri Venkateswara University, Tirupati-517502, Andhra Pradesh, India. 3985 VOLTAMMETRIC DETERMINATION OF PIOGLITAZONE IN PHARMACEUTICAL AND HUMAN URINE SAMPLES USING CARBON PASTE ELECTRODE Vishnu Priya M, Siva Prasad M, Sri Vidya D and NY Sreedhar* Electroanalytical Lab, Department of Chemistry, Sri Venkateswara University, Tirupati-517502, Andhra Pradesh, India Received for publication: May 09, 2015; Accepted: May 28, 2015 INTRODUCTION Pioglitazone (PGZ) is a thiazolidine dione antidiabetic agent, chemically it is (Rs)-5-(4_[2-5- ethylphyridin-2-yl) ethoxy] benzyl) thiazolidine - 2,4- dione. Pioglitazone modulates the transcription of the insulin sensitive genes involved in the control of glucose and lipid metabolism in the muscle, adipose tissue and in the liver. It is used in the treatment of type-1 diabetes mellitus. Pioglitazone targets insulin resistance and, hence, is used alone or in combination with insulin, metformin, or a sulfonyl urea as an antidiabetic agent [1]. PGZ decreases the plasma glucose concentrations insulin concentrations, and glycosylated hemoglobin. Additional favorable metabolic effects include decreased hepatic glucose output, lower free fatty acid concentrations, and improved lipid profiles. Thiazolidine diones such as pioglifazone help insulin to work more effectively [2]. Several spectrophotometric methods have been reported for the estimation of PGZ including ion- pair complex formation with bromothymol blue, bormo phenol blue and bromocresol purple and chlorophenol red as well as interaction with diazotized sulfanilic acid Chromatographic methods have been reported such as very rapid separation and quantification of PGZ HCl in the presence of metformin HCL on monolithic column as well as a stability indicating densitometric RP-TLC method [3-8]. Flow injection analysis, voltammetry, derivative spectrophotometry and capillary electrophoresis methods have been reported [9-14]. Carbon paste electrodes (CPEs) represent one of the most frequent types of working electrodes. A simple method of direct mixing of a solid modifier to the paste which was the commencement of explosive research activity in this field. Quite a few reviews are exclusively devoted to CPEs [15-21]. Carbon paste electrodes (CPEs) belong to promising electrochemical or bioelectrochemical sensors of wide applicability. The base of modified carbon pastes is usually a mixture of powdered graphite and nonelectrolytic binder. Figure 1: Structure of pioglitazone However most of these methods are time consuming therefore, focus of the present study was to develop an accurate, precise and robust voltammetric method for the determination of pioglitazone hydrochloride in pharmaceutical and urine samples. In the present work focused on an electrochemical analysis of PGZ in human urine samples with CPE. Therefore, a rapid and sensitive voltammetric method has been applied for the determination of PGZ in pharmaceutical and human urine samples. MATERIALS AND METHODS The voltammetry experiments performed with auto Lab PG STAT 101 supplied by Metrohm Autolab B.V., The Netherlands. A Three electrode system comprising of a Carbon paste electrode (CPE) as a working electrode, a saturated Ag/Agcl/Kcl as a reference electrode and Pt wire as a counter electrode Abstract: The electrochemical behaviour of Pioglitazone (PGZ) drug was studied using carbon paste electrode (CPE) in Britton Robinson (BR) buffer solution. Here Cyclic voltammetry and differential pulse voltammetric techniques were employed for this determination. The reduction process was shown to be irreversible over the pH range (2.0– 10.0) and the well-defined reduction peaks are obtained at -1.80V based on diffusion controlled. Effects of cathodic peak potential, current (Ipa), scan rate, pH, etc., have been discussed. A possible electro reduction mechanism was proposed. An analytical method was developed for the determination of pioglitazone in BR buffer solution at pH 6.0 as a supporting electrolyte. The cathodic peak current varied linearly with pioglitazone concentration in the range 6.25×10 −5 M to 3.25×10 −3 M with a limit of detection (LOD) of 2.65 × 10 − M and limit of quantification (LOQ) of 4.52 × 10 −8 M. The proposed method was successfully applied to the determination of pioglitazone in pharmaceutical and human urine samples. Key words: Pioglitazone; carbon paste electrode; cyclic voltammetry and differential pulse voltammetry; LOD