New degradation impurities at m/z 327.15 and m/z 311.16 using gradient UHPLC method with UV detection and highly selective QDa mass detection were observed during the ruxolitinib hydrobromide (RUX.HBr) : excipient binary mixture degradation study. High mass resolution LC-MS and nuclear magnetic resonance (NMR) techniques were employed to identify and fully characterize the degradation compounds. The degradation impurities were unambiguously identified as (R)-4-amino-6-(1-(2-cyano-1-cyclopentylethyl)-1H-pyrazol-4-yl)pyrimidine-5-carboxylic acid and (R)-3-(4-(6-amino-5-formylpyrimidin-4-yl)-1H-pyrazol-1-yl)-3-cyclopentylpropanenitrile and mechanism of their formation was proposed. It has been confirmed that the degradation products are formed in mixtures of RUX.HBr with some excipients in the presence of oxygen. Based on the forced degradation study, the chemically stable of pharmaceutical formulations were prepared to eliminate the formation of these impurities.
- MeSH
- hmotnostní spektrometrie MeSH
- kontaminace léku MeSH
- kyslík chemie MeSH
- magnetická rezonanční spektroskopie MeSH
- příprava léků MeSH
- pyrazoly analýza MeSH
- referenční standardy MeSH
- roztoky MeSH
- tablety analýza MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
New unknown impurity at m/z 421.15 was observed during the accelerated stability analysis (40 °C/75% relative humidity) in the multi-component tablets of amlodipine besylate by reversed-phase ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). UHPLC-MS and nuclear magnetic resonance (NMR) techniques were employed to identify and fully characterize the degradation compound. The degradation product was unambiguously identified as 3-ethyl 5-methyl 4-(2-chlorophenyl)-6-methyl-2-(morpholin-2-yl)-1,4-dihydropyridine-3,5-dicarboxylate and mechanism of its formation was proposed. It was confirmed that the degradation product was formed by the reaction of amlodipine with formaldehyde originating from the excipients present in the dosage form.
- MeSH
- amlodipin chemie MeSH
- časové faktory MeSH
- chromatografie s reverzní fází MeSH
- farmaceutická chemie metody MeSH
- fixní kombinace léků MeSH
- formaldehyd chemie MeSH
- hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
- hydrochlorthiazid chemie MeSH
- kontaminace léku * MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární struktura MeSH
- pomocné látky chemie MeSH
- stabilita léku MeSH
- valsartan chemie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
Unknown impurities were identified in ibuprofen (IBU) soft gelatin capsules (SGCs) during long-term stability testing by a UHPLC method with UV detection and its chemical formula was determined using high resolution/accurate mass (HRAM) LC-MS. Reference standards of the impurities were subsequently synthesized, isolated by semi-preparative HPLC and characterized using HRAM LC-MS, NMR and IR. Two impurities were formed by esterification of IBU with polyethylene glycol (PEG), which is used as a fill of the SGCs, and were identified as IBU-PEG monoester and IBU-PEG diester. Two other degradants arised from reaction of IBU with sorbitol and sorbitan, which are components of the shell and serves as plasticizers. Thus, IBU sorbitol monoester (IBU-sorbitol) and IBU sorbitan monoester (IBU-sorbitan ester) were identified. An UHPLC method was further optimized in order to separate, selectively detect and quantify the degradation products in IBU SGCs.
A novel and sensitive derivatization procedure for the determination of 2-cynaoacetamide in pharmaceutical samples using liquid chromatography with the fluorescence detection was discovered. The method is based on derivatization of 2-cynaoacetamide using 2-hydroxyacetophenone as a new derivatization reagent. The product of derivatization reaction was isolated and characterized using spectroscopic techniques namely LC-MS, NMR and IR. The structure of 2-cyanoacetamide derivative was unambiguously assigned as a 2-amino-4-phenylfuran-3-carboxamide. Two derivatization systems were optimized in terms of reaction temperature, reaction time, pH and concentration of 2-hydroxyacetophenone, and a new pre- and post-derivatization HPLC methods were developed. The separations on HPLC with pre-column derivatization were accomplished using stationary phase based on a XBridge C18 column (100×4.6, 3.5μm) and isocratic elution using the mobile phase acetonitrile - 0.1% formic acid (30:70, v/v). The separations on the HPLC with post-column derivatization were performed on stationary phase on a TSKgel Amide-80 column (150×4.6mm, 3μm). The mobile phase was a mixture of acetonitrile, methanol and 10mM sodium formate buffer at pH=4.5 in ratio 3:2:95 (v/v). Both HPLC methods were fully validated in terms of linearity, sensitivity (limit of detection and limit of quantification), accuracy and precision according to ICH guidelines. The pre-column derivatization method was linear in the range 1.1-2000μg/l with method accuracy≥98.2% and method precision RSD≤4.8%. The post-column derivatization method was linear in the range 12-2000μg/l. Method accuracy≥96.3% and method precision RSD≤3.5%. Proposed new methods were proved to be highly sensitive, simple and rapid, and were successfully applied to the determinations of 2-cynaoacetamide in pregabalin.
- MeSH
- acetofenony chemie MeSH
- hmotnostní spektrometrie MeSH
- indikátory a reagencie * MeSH
- magnetická rezonanční spektroskopie MeSH
- nitrily analýza MeSH
- pregabalin chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
- validační studie MeSH
Two new impurities were described and determined using gradient HPLC method with UV detection in retigabine (RET). Using LC-HRMS, NMR and IR analysis the impurities were identified as RET-dimer I: diethyl {4,4'-diamino-6,6'-bis[(4-fluorobenzyl)amino]biphenyl-3,3'-diyl}biscarbamate and RET-dimer II: ethyl {2-amino-5-[{2-amino-4-[(4-fluorobenzyl) amino] phenyl} (ethoxycarbonyl) amino]-4-[(4-fluorobenzyl)amino] phenyl}carbamate. Reference standards of these impurities were synthesized followed by semipreparative HPLC purification. The mechanism of the formation of these impurities is also discussed. An HPLC method was optimized in order to separate, selectively detect and quantify all process-related impurities and degradation products of RET. The presented method, which was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ) and selectivity is very quick (less than 11min including re-equilibration time) and therefore highly suitable for routine analysis of RET related substances as well as stability studies.
- Publikační typ
- abstrakt z konference MeSH
The gastrointestinal absorption of bisphosphonates is in general only about 1%. To address this problem mixtures of risedronate monosodium salt with twelve varied sugar alcohols, furanoses, pyranoses and eight gluco-, manno- and galactopyranoside derivatives as counterions were designed in an effort to prepare co-crystals/new entities with improved intestinal absorption. Crystalline forms were generated by means of kinetically and/or thermodynamically controlled crystallization processes. One hundred and fifty-two prepared samples were screened by means of FT-NIR and FT-Raman spectroscopy. No co-crystal was prepared, but noteworthy results were obtained. A new solid phase of risedronate monosodium salt generated in the presence of phenyl-β-d-galactopyranoside under thermodynamically controlled crystallization conditions was found and also characterized using solid state NMR spectroscopy, X-ray powder diffraction and differential scanning calorimetry. This new polymorph was named as form P. Interactions between risedronate monosodium salt and both carbohydrates were confirmed by means of molecular dynamics simulation. In the present study the relationships between the chemical structures of the studied compounds required for crystalline form change are discussed.
- MeSH
- diferenciální skenovací kalorimetrie MeSH
- difrakce rentgenového záření MeSH
- galaktosidy chemie MeSH
- krystalizace MeSH
- kyselina etidronová analogy a deriváty chemie MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární struktura MeSH
- Ramanova spektroskopie MeSH
- sacharidy chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Different pharmaceutical preparations against the common cold containing phenylephrine (PHE) and saccharose were studied. New impurities were discovered in these preparations after exposure using isocratic ion-pair chromatography separation on a C18 column. LC-MS and NMR techniques were employed to identify and to fully characterize these new compounds. The products were identified as 1-[5-(hydroxymethyl)-2-furyl]-2-methyl-1,2,3,4-tetrahydroisochinolin-4,8-diol and 1-[5-(hydroxymethyl)-2-furyl]-2-methyl-1,2,3,4-tetrahydroisochinolin-4,6-diol. Identification of these degradation products allowed to understand and to confirm their formation mechanism. The developed HPLC method separates of all known impurities and impurities originated from PHE as well.
- MeSH
- chemické modely MeSH
- chemické techniky analytické MeSH
- chromatografie kapalinová metody MeSH
- farmaceutická chemie metody MeSH
- fenylefrin analýza chemie MeSH
- hmotnostní spektrometrie metody MeSH
- kontaminace léku MeSH
- léčivé přípravky analýza MeSH
- magnetická rezonanční spektroskopie metody MeSH
- pomocné látky chemie MeSH
- sacharosa analýza MeSH
- stabilita léku MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
Mixtures of ibandronate monosodium salt with eleven gluco- and/or galacto-pyranoside derivatives as counterions were designed to prepare co-crystals with improved intestinal absorption. In general, gastrointestinal absorption of bisphosphonates after oral administration is approximately 1%. Co-crystals were generated by means of thermodynamically and/or kinetically controlled crystallization processes. Seventy-seven prepared samples were analyzed by means of FT-NIR, FT-Raman spectrometry and solid state NMR spectroscopy. New entities of ibandronate monosodium salt with phenyl-β-D-galactopyranoside were found and characterized. The absorption of these potential new co-crystals was investigated by means of PAMPA experiments. In the present study the relationships between the chemical structures of the studied compounds required for co-crystal generation are discussed.
Metallacarboranes and their derivatives are the recently discovered inhibitors of HIV protease. The main goal of this work was to study the interaction of parent metallacarborane derivatives with cyclodextrins (CD) differing in the inner cavity size. This interaction can improve the drug solubility and its transport to the cells. For ?-, ß- and ?-CD, NMR titrations with sodium cobalt(III) bis(1,2-dicarbollide) were performed at various CD concentrations. It was found that the greatest change in the 1H NMR chemical shift is observed at position 3 of CD on the inner broader rim of the cone-shaped molecule of CD. For ?-CD, the NMR titration curves correspond to the 1:1 stoichiometry and to the stability constant ca. 900. For ß- CD, simultaneous formation of 1:1 and 2:1 complexes and higher stability constants at least by two orders of magnitude follow from the titration curves. For ?-CD, more than two types of complexes are present. It was shown for ß- CD that the increased temperature does not significantly influence the titration curves. The model, consisting of a high number of adjustable parameters, for the determination of stability constants of the complexes must be confirmed by independent analytical methods such as isothermal calorimetry and X-ray structure determination.
