DEVELOPMENT AND VALIDATION OF DIFFERENTIAL PULSE POLAROGRAPHIC ANALYSIS OF FENOFIBRATE IN PURE AND PHARMACEUTICAL DOSAGE FORMS USING DROPPING MERCURY ELECTRODE

<p><strong>Objective: </strong>An easy, fast, accurate and sensitive differential pulse polarographic analysis for determination of fenofibrate (FEN) in pure and pharmaceutical dosage forms using dropping mercury electrode (DME) was applied.</p><p><strong>Methods: </strong>The method involves the electrochemical reduction of fenofibrate at DME by differential pulse polarographic analysis (DPPA). Different buffer solutions were used over a wide pH range (1.0–10.0). The best definition of the analytical signals was found in lithium perchlorate trihydrate buffer at pH 6.0 containing 24% (v/v) acetonitrile at-994 to-1025mV (versus Ag/AgCl).</p><p><strong>Results: </strong>Under optimized conditions the peak current (I_p) is linear over the range 0.0361-3.608 μg/ml. The DPPA was used successfully for the determination of FEN in pure and pharmaceutical dosage forms. The relative standard deviation did not exceed 2.1% for the concentration of FEN 0.0361 μg/ml. Regression analysis showed a good correlation coefficient (R²= 0.9994) between Ip and concentration at the mentioned range. The limit of detection (LOD) and the limit of quantification (LOQ) was to be 0.0025 and 0.0076 μg/ml, respectively. The proposed method was validated for linearity, precision and accuracy, repeatability, sensitivity (LOD and LOQ), robustness and specificity with an average recovery of 99.8-100.6%.</p><p><strong>Conclusion: </strong>The developed method is applicable for the determination of FEN in pure and different dosage forms with the assay of marketed formulations 99.8-104.0% and the results are in good agreement with those obtained by square-wave voltammetry (SWV) reference method.</p><p><strong>Keywords: </strong>Differential pulse polarographic analysis, Fenofibrate, Pharmaceutical formulations</p>

Analysis of Nicotine in Antismoking Pharmaceutical Products by Differential Pulse Polarography and Voltammetry

A fast and simple differential pulse polarographic method was developed for analysis of nicotine in various pharmaceutical formulations (chewing gum, tablets (drops) and patches). This method requires a simple liquid-liquid extraction procedure for chewing gum and patches, or a direct dilution in supporting electrolyte for tablets before polarographic analysis. The polarographic analysis was done in a Britton-Robinson buffer (pH 6.2) as supporting electrolyte. The multimode electrode from Metrohm was used as working electrode (dropping mercury electrode). This method was applied to the determination of the nicotine content in chewing gum, tablets and patches by using the standard addition method. The results are in good agreement with the content declared by the manufacturer. The method is fast, simple and reliable, and it is a complementary method to the chromatographic method being used today for quantitative analysis of nicotine in pharmaceutical formulations. The limit of quantification is assumed to be far below 0.1 mg/l in the polarographic vessel. The method uses simple dilution and/or extraction procedures for sample preparation before polarographic analysis. It is also shown that it is possible to use a glassy carbon electrode with a mercury film (MTFE electrode) for the determination of nicotine in antismoking pharmaceutical products.