Kinetics exploration of the isoniazid determination through the formation of AgNPs in pharmaceutical formulation

A simple, rapid, sensitive and accurate colorimetric method for the determination of isoniazid (ISONIAZID) in pure form and Pharmaceutical preparation is developed. The assay is based on the reaction of ISONIAZID with silver ions in the presence sodium hydroxide. Isoniazid reduces Ag+ ions to Ago state and then stabilizes the produced nanoparticles with change in the colour of solution which show maximum absorption at 399 nm. By measuring the absorbance of the produced nanoparticles at this wavelength isoniazid can be successfully estimated in the range 0.05–2.06 mg/L. The effect of time, NaOH concentration and isoniazid concentration on the synthesis of AgNPs was analyzed and optimized. These experiments showed that the absorbance of AgNPs at 399 nm varies linearly with the concentration of ISONIAZID in the range. The method showed good linearity with R2 value equal to 0.999. The limit of detection and quantification of the method are 14 μg/L and 46.5 μg/L. Kinetics of the reaction was also evaluated by applying various kinetic expressions to the experimental data which showed that pseudo second order kinetics are followed. The method was employed to the estimation of ISONIAZID in pure form, in tablets and in biotic fluids which gave good and accurate results. Thus the proposed method is very simple, less time consuming, economic in terms of chemicals and equipment and can be employed in a limited resources environment. [Display omitted]