Determination of ATP and its metabolites in dietary energy supplements by capillary electrophoresis

This study aimed to develop a simple and fast capillary electrophoresis (CE) method for the simultaneous determination of adenosine triphosphate (ATP) and its metabolites in dietary energy supplements. Reverse polarity separation mode for faster separation of the three strong negatively charged analytes and capillaries with a 25 µm inner diameter was employed. At -433 V/cm field strength at background electrolyte (BGE) consist with 0.1 M tris-HCl, 0.5 mM tetradecyltrimethylammonium chloride (TTAC) as positively charged surfactant and 0.3 mg/mL hydroxypropylmethylcellulose (HPMC) to reduce the electroosmotic flow (EOF), a complete separation of the three species were achieved in less than 15 minutes. The data acquisition was conducted at a wavelength of 254 nm. Three different commercialised dietary energy supplements were analysed

Determination of ATP and its metabolites in dietary energy supplements by capillary electrophoresis

Abstract This study aimed to develop a simple and fast capillary electrophoresis (CE) method for the simultaneous determination of adenosine triphosphate (ATP) and its metabolites in dietary energy supplements. Reverse polarity separation mode for faster separation of the three strong negatively charged analytes and capillaries with a 25 µm inner diameter was employed. At -433 V/cm field strength at background electrolyte (BGE) consist with 0.1 M tris-HCl, 0.5 mM tetradecyltrimethylammonium chloride (TTAC) as positively charged surfactant and 0.3 mg/mL hydroxypropylmethylcellulose (HPMC) to reduce the electroosmotic flow (EOF), a complete separation of the three species were achieved in less than 15 minutes. The data acquisition was conducted at a wavelength of 254 nm. Three different commercialised dietary energy supplements were analysed

Development of a HPLC Method for the Determination of Cyclosporine A From Chitosan Nanoparticles

A reversed-phase high performance liquid chromatographic method was developed for the determination of cyclosporine A from chitosan nanoparticles. Ibuprofen was used as internal standard. The separation was achieved on a Phenomenex C18 column (150 x 4.6mm, 5 mu m) using 60: 20: 20, acetonitril: methanol: water mixture at pH 4 as mobile phase under isocratic conditions. The system was operated at 80 degrees C and the flow rate of mobile phase was adjusted to 1 mL/min. The detection wavelength was set at 205 nm. The calibration curve was linear from 2 to 150 mu g/mL with correlation coefficient values from 0.9994 to 0.9997. The lower limit of quantification 2 mu g/mL and limit of detection was 0.5 mu g/mL. Recovery was 99-101 % and the intra-and inter-day coefficients of variation were 0.94-2.32 and 2.52-3.45 %, respectively depending on the concentration. The method was found to be specific, accurate, precise and sensitive for the determination of cyclosporine A from chitosan based drug delivery systems

Determination Of Regional Intestinal Permeability Of Diclofenac And Metoprolol Using A Newly-Developed And Validated High Performance Liquid Chromatographic Method

Purpose: To develop a simple and rapid reversed-phase high performance liquid chromatographic (HPLC) method with UV detection for the simultaneous determination of diclofenac, metoprolol tartrate, phenol red and propyl paraben in intestinal segments. Methods: The mobile phase consisted of 55% methanol, 45% of 12.5 mM potassium dihydrogen phosphate (KH2PO4) aqueous solution, adjusted to pH 7.0 using 0.2 N sodium hydroxide (NaOH) solution, and to which 0.3% (v/v) triethylamine was added. Analysis was run at a flow rate of 1.0 mL/min with a 12 min total run time at ambient temperature. The developed method was successfully applied to determination of the analytes in samples obtained from in situ single pass intestinal perfusion (SPIP) studies. Results: The calibration curves were linear for all compounds (r > 0.999) with a limit of detection (LOD) of 0.005, 0.1, 0.075 mu g/mL, and limit of quantification of 0.1, 0.3, 0.2 mu g/mL for metoprolol tartrate, phenol red and diclofenac respectively. The coefficient of variation for intra-day and inter-day precision was < 5% and accuracy was between 98 and 102%. Based on SPIP and HPLC studies, the estimated mean permeability in jejunum, ileum and colon was 0.319 +/- 0.184, 0.639 +/- 0.241 and 0.84 3 +/- 0.517 x 10(-4) cm/sec, respectively, for metoprolol tartrate while the corresponding permeability values were 1.585 +/- 0.729, 1.154 +/- 0.433 and 1.775 +/- 1.576 x 10(-4) cm/sec for diclofenac. Conclusion: The findings indicate that diclofenac is a highly permeable compound and its absorption occurs throughout the intestinal tract. Furthermore, the developed method is suitable for the analysis of diclofenac and metoprolol in intestinal regions.WoSScopu

Design, Synthesis, and Biological Evaluation of Pyridazinones Containing the (2-Fluorophenyl) Piperazine Moiety as Selective MAO-B Inhibitors

Twelve pyridazinones (T1&ndash;T12) containing the (2-fluorophenyl) piperazine moiety were designed, synthesized, and evaluated for monoamine oxidase (MAO) -A and -B inhibitory activities. T6 was found to be the most potent MAO-B inhibitor with an IC50 value of 0.013 &micro;M, followed by T3 (IC50 = 0.039 &micro;M). Inhibitory potency for MAO-B was more enhanced by meta bromo substitution (T6) than by para bromo substitution (T7). For para substitution, inhibitory potencies for MAO-B were as follows: -Cl (T3) &gt; -N(CH3)2 (T12) &gt; -OCH3 (T9) &gt; Br (T7) &gt; F (T5) &gt; -CH3 (T11) &gt; -H (T1). T6 and T3 efficiently inhibited MAO-A with IC50 values of 1.57 and 4.19 &micro;M and had the highest selectivity indices (SIs) for MAO-B (120.8 and 107.4, respectively). T3 and T6 were found to be reversible and competitive inhibitors of MAO-B with Ki values of 0.014 and 0.0071, respectively. Moreover, T6 was less toxic to healthy fibroblast cells (L929) than T3. Molecular docking simulations with MAO binding sites returned higher docking scores for T6 and T3 with MAO-B than with MAO-A. These results suggest that T3 and T6 are selective, reversible, and competitive inhibitors of MAO-B and should be considered lead candidates for the treatment of neurodegenerative disorders like Alzheimer&rsquo;s disease