Development and validation of a HPLC method for the determination of metronidazole, oxytetracycline and furazolidone in veterinary formulations

Authors: Violeta Tauber (Giugiu), Viorica Chiurciu
Affiliation: Romvac Company S.A.

An isocratic reversed phase high performance liquid chromatographic method with DAD detection was developed for the analysis of metronidazole, oxytetracycline and furazolidone. The mobile phase consisted of pH 2.5 phosphate buffer solution, methanol and acetonitrile (70 : 18 : 12). The UV detection was carried out at 264 nm, and the flow rate was 1.100 mL / min. The separation was carried out on a Nucleosil C18 column, 5 μm 250 mm x 4.6 mm, which was maintained at 25°C. This method was validated by system suitability parameters, linearity, limits of detection and quantification, precision and accuracy.

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A validated HPLC method for determination of furazolidone and oxytetracycline in the presence of related substances

Author: Violeta Giugiu                                                                                                                       Affiliation: Romvac Company S.A., Bucharest

The objective of the current study was to develop a simple, precise, rapid and accurate reverse phase liquid chromatographic method for the quantitative determination on furazolidone, oxytetracycline and related substances in veterinary formulation. This formulation was submitted to accelerated degradation studies under acidic, alkaline and oxidative conditions, exposure to light and thermal stability. The separation of furazolidone, oxytetracycline and degradation products was achieved on BDS Hypersil C18 (250mmx4.6mm, i.d. 5 µm particle size) with gradient mobile phase containing methanol and 80 mM dipotassium phosphate pH 7,5 (20/80). The flow rate was 1.0 mL/min and detection was set at 254 nm, at 25 °C. The developed method was validated with respect to linearity, limits of detection and quantification, specificity, accuracy, and precision.

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Simultaneous determination of related substances of oxytetracycline in pharmaceutical semi solid form by Hight Performace Liquid Chromatography

Author: Violeta Giugiu                                                                                                                               Affiliation: Romvac Company S.A., Bucharest

Simultaneous determination of oxytetracycline, 4-epioxytetracycline, alpha-apooxytetracycline, tetracycline, beta-apooxytetracycline on C18 columns has been accomplished using a high performance liquid chromatographic method with UV detection. Separation was achieved on a Hypersil BDS RP-C18 column with a mobile phase consisted of acetonitrile-methanol-80mM dipotassium phosphate pH 7,5 at a flow rate of 0,7 mL min-1. Absorbance measurements were held at 254 nm.

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Some aspects regarding impurities profile in fipronil – HPLC method

Authors: Ana Csuma, Cornelia Pîrlog                                                                                             Affiliation: S.N. Institutul Pasteur S.A., Bucuresti

Using a substance as active pharmaceutical ingredient in veterinary drug formulation requires the characterization of this substance as content in active compound and so in terms of impurities possible present in it, the latter being a mandatory requirement for a drug application. Fipronil is a synthetic product belonging to pesticide class used in veterinary practice to manufacture of some products against fleas, given spot–on or in form of spray, in cats and dogs. The main impurities in fipronil include process related impurities and degradation products as a result of exposure to environmental conditions: reduction, oxidation, photolysis and hydrolysis. A HPLC method suitable for analytical separation of fipronil from its impurities was established. Separation was achieved on a reversed phase column using a mixture of methanol, acetonitrile and water as mobile phase. In the chosen chromatographic conditions the resolution between fipronil and its sulphone (the main impurity) was >3 and the tailing factor (T) < 2.0. Related impurities have absorbed in the same band of UV wavelength as the main compound fipronil. Comparing the area of impurities obtained for sample solution with the area of the main peak in diluted standard solution allowed the detection of impurities at concentration

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