title: Electrochemical behavior of the antituberculosis drug isoniazid and its square-wave adsorptive stripping voltammetric estimation in bulk form, tablets and biological fluids at a mercury electrode.
abstract: Isoniazid, pyridine-4-carboxylic acid hydrazide, is an antituberculosis-agent, which is used to prevent the development of clinical tuberculosis. A validated square-wave adsorptive cathodic stripping voltammetric procedure for the trace determination of the bulk drug at the hanging mercury drop electrode (HMDE) has been developed. Under the optimized conditions, (accumulation potential=-0.9 V, accumulation time=50-300 s, scan increment=8 mV, pulse-amplitude=25 mV, frequency=120 Hz and acetate buffer at pH 5.5) isoniazed generated two irreversible cathodic peaks. The first peak current showed a linear dependence with the drug concentration over the range 5 x 10(-10)-21 x 0(-6) M. The mean percentage recoveries, based on the average of five replicate measurements, for 7 x 10(-9) and 5 x 10(-8) M isoniazid were 97.71+/-2.93 and 99.76+/-0.77, respectively. The achieved limits of detection (LOD) and quantitation (LOQ) were 1.18 x 10(-10) and 3.93 x 10(-10) M isoniazid, respectively. The procedure was applied to the assay of the drug in tablets (Isocid and T.B. Zide), spiked human serum and urine with mean percentage recoveries of 97.81+/-1.49, 97.45+/-2.09, and 97.08+/-1.06, respectively. The limits of detection of 1.47 x 10(-9) and 2.4 x 10(-8) M, and quantitation of 4.9 x 10(-9) and 8 x 10(-8) M drug in human serum and urine, respectively, were achieved. The mean values of the various pharmackinetic parameters of isoniazid (C(max), T(max), t(1/2), AUC, and K(e)), estimated from analysis of plasma of two volunteers by means of the proposed procedure were similar to literature values.
authors: Chemistry Department, Faculty of Science, Tanta University, 31527 Tanta, Egypt. mmghoneim@usa.net
authors: M M
authors: MM
authors: Ghoneim
authors: K Y
authors: KY
authors: el-Baradie
authors: A
authors: A
authors: Tawfik
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000097:blood* / Q000737:chemistry / Q000652:urine*; D004563:Electrochemistry; D004566:Electrodes; D006801:Humans; D007538:Isoniazid / Q000097:blood* / Q000737:chemistry / Q000652:urine*; D008297:Male; D008628:Mercury / Q000032:analysis*; D008875:Middle Aged; D004364:Pharmaceutical Preparations; D013223:Statistics as Topic; D013607:Tablets
chemical_list: D000995:Antitubercular Agents; D004364:Pharmaceutical Preparations; D013607:Tablets; D008628:Mercury; D007538:Isoniazid