%0 Journal Article %T Novel Reagents for the Spectrophotometric Determination of Isoniazid %A Divya N. Shetty %A Badiadka Narayana %A Seranthimata Samshuddin %J ISRN Spectroscopy %D 2012 %R 10.5402/2012/869493 %X Isoniazid is an antitubercular drug, widely used for tuberculosis. Owing to its importance in therapeutics, the present study aims to develop simple method for the spectrophotometric determination of isoniazid (INH). Two novel reagents, epichlorohydrine (ECH) and 4-hydroxyphenaylchloride (HPC) are used for the spectrophotometric determination of INH. Based on the nucleophilic substitution reactions of INH with EPI & HPC in basic medium, rapid, simple, inexpensive, precise, and accurate visible spectrophotometric method is proposed for the determination of INH in bulk drug and in formulations. Method involves the reaction of INH with EPI and HPC in basic medium to form yellow-colored chromogen, measuring the absorbances at 405 and 402£¿nm for INH-EPI & INH-HPC, respectively. The optimum experimental conditions have been studied. The absorbance was found to increase linearly with the concentration of the drug and formed the basis for quantification. The calibration graphs were linear from 2.00¨C22.00£¿¦Ìg£¿mL£¿1 and 20.00¨C120.00£¿¦Ìg£¿mL£¿1 for INH-EPI & INH-HPC, respectively. The apparent molar absorptivity and Sandell's sensitivity are calculated to be 0 . 5 1 ¡Á 1 0 4 & 0 . 1 0 ¡Á 1 0 4 £¿L mol£¿1£¿cm£¿1 and 0.027 & 0.134£¿¦Ìg£¿cm£¿2 for INH-EPI & INH-HPC, respectively. The procedure is used to determine INH in pharmaceutical products. The associated pharmaceutical materials do not interfere in the measurements. 1. Introduction The enhanced prevalence of infectious diseases threatens world population. Tuberculosis (TB) is characterized as a chronic bacterial infection caused by a germ called Mycobacterium tuberculosis. TB is contagious and spreads through the air when a person with TB of the lungs or throat coughs, sneezes, or talks. Worldwide statistics on tuberculosis surprisingly reveals that, one-third of the world¡¯s population, over 2 billion people, carry the bacillus that causes TB and 2 million people die of the disease each year. Tuberculosis is on the increase in recent years, largely owing to HIV infection, immigration, increased trade, and globalization [1]. Among the many drugs discovered for the treatment of TB, isoniazid (INH) is one of the powerful drug candidates. The discovery of INH was based on the nicotinamide activity against tubercle bacilli in the animal model observed by Chorine in 1945 [2] and the reshuffling of chemical groups in the thiosemicarbazone [3, 4]. INH represented a major milestone in the chemotherapy of TB because it is highly active, inexpensive, and without significant side effects [5, 6]. INH keeps on to be the cornerstone of all %U http://www.hindawi.com/journals/isrn.spectroscopy/2012/869493/