Development and Application of Kinetic Spectrophotometric Method for the Determination of Metronidazole

Purpose: To develop an improved kinetic-spectrophotometric procedure for the determination of metronidazole (MNZ) in pharmaceutical formulations.Methods: The method is based on oxidation reaction of MNZ by hydrogen peroxide in the presence of Fe(II) ions at pH 4.5 (acetate buffer). The reaction was monitored spectrophotometrically by measuring the rate of change of absorbance at 317nm.Results: The optimum operating conditions for reagent concentrations and temperature were established. Linear calibration curve was obtained in the range of 85.77 – 513.45ng mL-1 with standard deviation from 1.77 to 4.55 %-. The optimized conditions yielded a theoretical detection limit of 15.20 ng mL-1 based on 3.3So criterion. Commonly used excipients and other additives such as talc, glucose, fructose, lactose, starch, magnesium stearate, microcrystalline cellulose and several ions were found not to have interference.Conclusion: The developed method is sensitive, accurate and reproducible and could be used for routine analysis of metronidazole in pharmaceutical preparations.Keywords: Metronidazole, Kinetic spectrometry, Validation, Pharmaceutical preparation

The elementome of calcium-based urinary stones and its role in urolithiasis

Urolithiasis affects around 10% of the US population with an increasing rate of prevalence, recurrence and penetrance. The causes for the formation of most urinary calculi remain poorly understood, but obtaining the chemical composition of these stones might help identify key aspects of this process and new targets for treatment. The majority of urinary stones are composed of calcium that is complexed in a crystalline matrix with organic and inorganic components. Surprisingly, mitigation of urolithiasis risk by altering calcium homeostasis has not been very effective. Thus, studies to identify other therapeutic stone-specific targets, using proteomics, metabolomics and microscopy techniques, have been conducted, revealing a high level of complexity. The data suggest that numerous metals other than calcium and many nonmetals are present within calculi at measurable levels and several have distinct distribution patterns. Manipulation of the levels of some of these elemental components of calcium-based stones has resulted in clinically beneficial changes in stone chemistry and rate of stone formation. The elementome - the full spectrum of elemental content - of calcium-based urinary calculi is emerging as a new concept in stone research that continues to provide important insights for improved understanding and prevention of urinary stone disease