Development of a pH induced dispersive solid-phase extraction procedure for extraction of favipiravir from biological samples and its determination by capillary electrophoresis

Abstract

Introduction: The analysis of drugs in real samples cannot be done directly due to the complexity of their matrix and the low concentration of drugs, and it requires the implementation of preparation methods in order to remove impurities and interfering factors and pre-concentrate the anayltes.purpose: To develop a pH-induced solid phase extraction method to extract favipiravir from biological samples and measure it by electrophoresis.Procedure: 5 ml of biological sample (after protein extraction and dilution) was transferred to a test tube and its pH was adjusted to 9 using borate buffer. After dissolving 0.125 grams of sodium-chloride (equivalent to 2.5% by weight-volume) in the test solution, 25 mg of biotin was also dissolved in it. Then, 300 microliters of hydrochloric acid (with a concentration of 0.5 M) was added to the test solution. During this process, the solubility of the adsorbent is reduced and it is distributed in the form of particles. To increase the contact surface of the absorbent, the mixture was ultrasonicated for 1 minute and then centrifuged for 10 minutes at a speed of 4000 rpm. The supernatant solution was discarded and 100 microliters of acetonitrile was added as a desorption solvent on the absorbent and ultrasonicated for 3 minutes, then centrifuged for 10 minutes and the supernatant was mixed with 100 microliters of 0.05 M borate buffer. Finally, the mixture was injected into the capillary electrophoresis device after filtering.Results: The limit of detection and quantification were 60 and 200 ng/ml, respectively, and the extraction efficiency was 72% and the relative standard deviation was below 8.2%.Conclusion: The developed method is an easy and efficient method for analyte extraction, and its acceptable accuracy and precision show that it can be used in isochemistry and biopharmaceutical studies to determine the concentration profile of favipiravir.