Abstract

ESTIMATION OF INORGANIC (METAL) IONS IN SOME OF THE MARKETED FORMULATIONS BY FLAME EMISSION SPECTROSCOPY

Sumanth Prabhu*, Subhash Kale and Dr. A. Venkatachalam

Abstract

A metal ion in aqueous solution (aqua ion) is a cation with single or multiple positive charge, dissolved in water, of chemical formula [M(H2O)n]z+. Aqua ions are present in most natural waters. Na+, K+, Mg2+ and Ca2+ are major constituents of sea and ground water. The concentrations of sodium, potassium, magnesium and calcium in blood are similar to those of seawater. Blood also has lower concentrations of essential elements such as iron and zinc. Many are essential in our diets in varying quantities due to their metabolic importance in human body. On the other hand, metals have played an important role in medicine for years in the form of supplement medicines. In addition, a number of drugs and potential pharmaceutical agents also contain metal-binding or metalrecognition sites, which can bind or interact with metal ions and potentially influence (increase or decrease) their bioactivities. Different metal ions which are toxic at higher concentrations are also useful for maintaining life processes at lower concentrations and are even effective in the modification of some well-established drug molecules towards their better action.[1] Controlling and minimizing the side effects of these metal ions[5] (termed metal impurities here) from these drugs is a key issue in assuring the safety of drug therapy. To make drugs serve their purpose various chemical and instrumental methods were developed at regular intervals which are involved in the estimation of drug. The purpose of the present study was to develop estimate the inorganic (metal) ions in some of the oral dosage drug products by Flame emission spectroscopy (FES). An internal standard technique is proposed in order to reduce sample preparation and injection related errors thereby improving method accuracy. Proposed method is validated as per ICH[4,7] guidelines and was employed to perform the recovery estimation in this study.

Keywords: Inorganic Ions, Metal Ions, Impurities, Method validation, Oral dosage drug products, Flame emission spectroscopy, Internal standard, Cation, Metal impurities.