Visible Quantitative Methods for the Estimation of Furosemide in Pure form and Pharmaceutical Formulations

Aims: Design of technical methods for the determination of Furosemide in its pure and pharmaceutical dosage form using spectral methods. Study Design: planned and executed to estimate Furosemide by using Visible spectrophotometric in pure and pharmaceutical dosage form. Place and Duration of Study: Laboratory of Analytical Research, chemistry department, college of Science, University of Mosul ,Mosul-Iraq, during the period of April 2021 to August 2021. Methodology: Furosemide, the commercially known drug Lazix, which is important in the treatment of heart diseases and high blood pressure. This study was carried out using JASCO V – 630, double-beam computerized UV-Visible spectrophotometer, with 1 cm matched cell, and HANA pH meter was used for reported pH readings. Results: The reaction between Furosemide and bromo-phenol blue, xylenol orange, and chromazorol S. The decreasing in the intensity of the resulted colored complex was measured using bromo-phenol blue, xylenol orange, While the increasing of the color intensity was measured in the method (C). These three methods were based on charge transfer reaction. The limits of Beer's law for method (A) 0.4-32µg. mL-1, method (B) 1-32 and method (C) were 0.8-32 depending on the level of concentration, while the values ​​of the molar absorption coefficient 1.4×104, 2.1×104 and 1.57×104 l.mol-1.cm-1 for the first, second and third method respectively. Sandel's significance also was calculated for these three methods, 0.0157 μg.cm-2 for the first method, 0.0236 μg.cm-2 for the second method, while the third method was 0.0210 μg.cm-2. The method has been successfully applied for the determination of furosemide in its pure form and in some of its pharmaceutical preparations Conclusion: The proposed methods were validated in terms of linearity, range, Accuracy, precision, Specificity, Robustness. The proposed methods were successfully applied to the estimation of Furosemide in pharmaceutical dosage form, method (B) was experimentally considered as a best method depending on the best values of molar absorptivity, stability of the resulted complex, and the linearity of the method (B) .