Voltammetric assays and behavior of norfloxacin and nalidixic acid antibacterial drugs

Abstract

This thesis describes the work done on the voltammetric assays, physicochemical behavior, and mechanistic studies of norfloxacin and nalidixic and antibacterial drugs at the dropping mercury electrode (DME) and at the hanging mercury drop electrode (HMDE). Easy, precise, accurate and fast analytical procedures have been developed for the quantitative determination of norfloxacin and nalidixic acid in formulated tablets using differential pulse polarography (DPP), linear scan voltammertry (LSV) and adsorptive striping voltammetry (AdSV). The voltammetric behavior and mechanistic study of norfloxacin and natidixic acid were investigated. Norfloxacin was found to be reduced in one electron step in strongly acidic and in alkaline solution. Howevr, it is reduced in 2 one electron steps in slightly acidic to slightly alkaline solutions(pH 5.5 - 8.0). The two main reduction waves were found to be irreversible and diffusion controlled with scan rates > 20 mV/sec. However, the other smaller waves showed different degree of reversibility depending on the scan rate and were found to be adsorption controlled. Nalidixic acid is found to be reduced in 2 one electron steps in strongly acidic medium and in slightly acidic to slightly alkaline solutions. However, it is reduced in one electron only in alkaline solutions. Its reduction processes were found to be completely irreversible and diffusion controlled.