Habla de Distintos Tipos de Streeping

Current Pharmaceutical Analysis, 2009 , 5, 127-143 127 1573-4129 /09 $55.00+.00 © 2009 Bentham Science Publishers Ltd. Principles and Techniques of Electroanalytical Stripping Methods for Pharmaceutically Active Compounds in Dosage Forms and Biological Samples Sibel A. Ozkan* Ankara Un iversity, Fa culty of Ph armacy , Departm ent of Ana lytical Ch emistry, 0 6100, Ta ndoga n, Ankara, Turkey Abstract: A review of the applications, principles, advantages of stripping voltammetric techniques, namely anodic, cathodic, abrasive, adsorptive stripping voltammetry and potentiometric stripping analysis is presented. Stripping voltammetric methods in pharmaceutical analysis are discussed and the generally applicable procedure is given. The use and advantages and disadvantages of these techniques at different electrodes are discussed. The analytical applications of stripping techniques to pharmaceutically active compounds are also discussed. Various selected determination studies on drugs by stripping techniques from pharmaceutical dosage forms and biological samples are reviewed. Keywords: Adsorptive stripping, Anodic stripping, Biological samples, Cathodic stripping, Determination, Drugs, Potenti- ometric stripping. INTRODUCTION Electroanalytical methods are among the most powerful and popular techniques used in analytical chemistry [1-13]. Electrochemistry affords some of the most sensitive and in- formative analytical techniques in the pharmaceutical analysis area. Electroanalytical methods such as linear sweep, cyclic, differential pulse, square wave, stripping voltammetric techniques and chronoamperometry are not only capable of determining trace amounts of an electroactive drug compounds, but also supply useful informa tion concern ing its physical and chemical proper ties. The pharmac eutical and biomedical analysis is a mong th e most importan t branches of applied analytical chemistry. Analytical measurement proce- dures should have a critical role in drug analysis as well as in biological samples [1-8]. Electroch emistry has always pro- vided analytical techniques characterized by instrumental simplicity, moderate cost and portability. Moreover, in some cases there is a relationship between electrochemical behav- ior and mechanism of electroactive drug compounds. The knowledge of the mechanism of their electrode reactions can give the useful clue in elucidation of the mechanism of their interacti on with living cells and their fate in the human body after administration as the dosage form. In many cases, modern electroanalytical methods can be viable alternative to more frequently used spectrometric or separation methods. The knowledge of an electrode process of drug compounds provides a useful aid for understanding of its enzymatic processes and oxidation/reduction mecha- nisms after administration in the body. The characteristics of electroanalyti cal techniques make these trace amount of drug analysis particularly well suited for automatic in situ *Address correspondence to this author at the Ankara University, Faculty of Pharmacy, Department of Analytical Chemistry, 06100, Tandogan, Ankara, Turkey; Tel/Fax: 00 90 312 223 82 43; E-mail: [email protected] speciation measurements, with or without minimum sample change. Electroanalytical methods are well suited for sens- ing, monitoring and detection of certain types of analytes [1- 6]. The quantitation of trace and ultra-trace components in complex samples of clinical or industrial origin represents an important task of mod ern electroanalytical chemistry. The most widespread electroanalytical methods are voltammetry and polarography. Modern electroanalytical methods are usually applied in a vessel containing a three electrode cell system. Polarography is a special branch of electrochemistry where the working electrode is dropping mer- cury. Solid or static electrodes are used as working electrodes in voltammetric techniques. The commonly used voltammetric methods are cyclic, linear sweep, pulse (normal pulse (NPV), differen tial pulse (DPV), square wave (SWV and staircase), alternative current and stripping voltammetry [1-10]. In these techniques, cyclic voltammetry is not sensitive enough for trace amount determination of pharmaceutical compounds but it is useful to optimize analytical condi- tions and it gives some important information about the oxidation/reduction mechanism of drug compounds. Direct oxidation or reduction methods, such as DPV or SWV have been used for the determinat ion of trace amount of drug compounds without any separation or precipitation steps [10- 22]. The aim of the present paper is to evaluate and give some brief information of the stripping methods and to outline some of its applications for the determination of pharmaceutically active compounds in their dosage forms and in biological fluids. An attempt was made to choose only applica- tion on drug compounds and readily available publications describing some advances in methodology and applicati ons. One of the most important voltammetric analytical techniques is stripping voltammetry. Stripping analysis is an ex- tremely sensitive electrochemical technique for measuring trace amount of pharmaceutically active compound either its

Habla de Distintos Tipos de Streeping

Documents