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Study of degradation behavior of abacavir using a diamond film electrode
Pražáková, Lucie ; Kubíčková, Anna (advisor) ; Kozlík, Petr (referee)
In this work the electrochemical degradation behavior of the drug abacavir is studied with the use of boron-doped diamond electrode. Oxidative degradation of the active substance abacavir, used to treat patients with HIV disease, was studied in a batch of three-electrode and two-electrode settings. In this work, the characteristics of five working boron-doped diamond electrodes, differing in a boron/carbon doping ratio of 500 ppm, 1000 ppm, 2000 ppm, 4000 ppm and 8000 ppm, were studied. The degradation in the three-electrode arrangement took place under potenciostatic electrolysis at potentials from 0,6 V to 2,0 V. The degradation in the two-electrode arrangement took place under conditions of potenciostatic electrolysis at higher potentials from 2,0 to 4,5 V. Optimal degradation, to the required values up to 25 %, was achieved at a potential of 3,5 V for an oxidation time of 10 minutes on a boron-doped diamond electrode with a boron/carbon doping ratio of 500 ppm and 1000 ppm. Separation and determination of abacavir and its degradation products were performed by ultra-high performance liquid chromatography with a mass detector. The degradation of abacavir produced two known degradation products, DP1 with relative retention times of 0,40 and DP2 with relative retention times of 0,45. The...
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Forced degradation study of canagliflozin with the use of HPLC
Máchalová, Jitka ; Křížek, Tomáš (advisor) ; Sobotníková, Jana (referee)
In this work a method for determination of canagliflozin and its degradation products by HPLC with UV and MS detector was developed. The developed method was used to study the forced degradation of canagliflozin and to investigate the major degradation products resulting from exposure of canagliflozin to oxidative stress. Canagliflozin is a phenolic glycoside derivative and a glucose-sodium transporter 2 inhibitor that stimulates urinary glucose excretion by suppressing glucose reabsorption from the proximal tubule in the kidneys. Canagliflozin is used to control blood glucose levels in patients with type 2 diabetes. In an optimized method, an Agilent Poroshell 120 SB-Aq (2.1 × 100 mm, 2.7 µm) column was used and a mixture of buffer (10mM HCOOH adjusted with ammonium hydroxide to pH 3.5) and acetonitrile as a mobile phase. The method validation included testing of accuracy, repeatability, the limit of detection and quantification, linearity and linear dynamic range, the robustness of the method, and testing of sample stability. The limit of detection of the method was 8.9·10-5 mg ml-1 (2.0·10-7 mol l-1 ) and the limit of quantification was 3.0·10-4 mg ml-1 (6.8·10-7 mol l-1 ). At a concentration of 0.3 mg ml-1 , the repeatability (n = 7) was 0.17 % and 0.75 % for the retention time and the peak...
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