pectins and acetonitrile

A simple, rapid, and stability indicating reversed-phase high-performance liquid chromatography (HPLC) method of analysis for budesonide, a novel glucocorticoid prescribed for inflammatory bowel disease, was successfully developed. Budesonide is an epimeric mixture and both the epimers have similar anti-inflammatory activity. All the analytical methods reported in the literature are long and are based on separation of the epimers, thus our objective was to obtain a single sharp peak of the drug and to separate the drug peak from all the other degradation products. The method, was used to quantify budesonide in the developed formulation, employed a Kromasil C8, (150 mm x 4.6 mm) column with an isocratic mobile phase of acetonitrile-phosphate buffer (pH 3.2-0.025 M) (55:45 v/v), at a flow rate of 1.1 mL/min. Budesonide was detected by an ultraviolet detector at 244 nm. The method was validated for linearity, precision, repeatability, sensitivity, and selectivity. Selectivity was validated by subjecting stock solution of budesonide to acidic, basic, oxidative, and thermal degradation. The retention time of budesonide was about 4 min with symmetrical peaks. The method was linear over a concentration range 1-50 microg/mL (R2=0.9995). The limit of detection of budesonide was 0.1 microg/mL and the limit of quantitation was 0.25 microg/mL. The peaks of the degradation products did not interfere with the peak of budesonide. The developed method was used to quantify budesonide in budesonide-loaded micro-particles. Excipients present in the micro-particles did not interfere with the analysis and the recovery of budesonide from micro-particles was quantitative.

Topics: Acetonitriles; Anti-Inflammatory Agents; Budesonide; Chromatography, High Pressure Liquid; Drug Stability; Hydrogen-Ion Concentration; Microspheres; Pectins; Reproducibility of Results; Temperature; Time Factors

A procedure was developed to measure the content of methanol in pectins after the base-catalysed hydrolysis of galacturonic acid methyl esters and oxidation of released methanol with potassium permanganate followed by condensation of the resulting formaldehyde (HCHO) with 2,4-dinitrophenylhydrazine (DNPH) dissolved in acetonitrile. The constant yields of resultant formaldehyde 2,4-dinitrophenylhydrazone (HCHO-DNPH derivative) were obtained at molar ratios of DNPH/HCHO higher than 5. The separation of the HCHO-DNPH derivative from DNPH reagent was achieved by isocratic reversed-phase HPLC equipped with the spectrophotometric detector set at a wavelength of 351 nm. The calibration curve was linear in the methanol concentration range between 0.04 and 15 micromol/ml (R=0.9995). The total recovery from pectin solutions spiked with methanol was equal to 100.6+/-5.1%.

Topics: Acetonitriles; Chromatography, High Pressure Liquid; Formaldehyde; Indicators and Reagents; Methanol; Oxidation-Reduction; Pectins; Phenylhydrazines; Reproducibility of Results