LC-MS/MS Method Applied to the Detection and Quantification of Ursodeoxycholic Acid Related Substances in Raw Material and Pharmaceutical Formulation

Abstract: Objective: To develop a highly sensitive LC-MS/MS (liquid chromatography-mass spectrometry/mass spectrometry)method applied to the detection and quantitation of UDCA (ursodeoxycholic acid) related substances such as CA (cholic acid), DCA(deoxycholic acid), CDCA (chenodeoxycholic acid) and LCA (lithocholic acid) in raw material and pharmaceutical formulation.Methods: The method was validated for specificity, linearity, accuracy, precision, robustness. A triple quadrupole mass detector wasemployed, equipped with an ESI (electrospray ionization) source operated in the negative ion mode. The chromatographic systemconsisted of a Symmetry C18 column (150 mm × 4.6 mm, id; particle size 5 µm) and methanol-acetonitrile-ammonium acetate (pH 7.6;10 mM) (40:40:20, v/v/v) as the mobile phase. The chromatographic conditions were 25 uL injection volume, flow rate of 0.4 mL/minand column temperature set at 35 °C. Key findings: The method requires a minimum sample amount and presents very low LOD(limits of detection) for CA (0.29 ng/mL), DCA (0.59 ng/mL), CDCA (0.13 ng/mL) and LCA (0.44 ng/mL) in comparison to LCmethods coupled to different detectors like UV (ultraviolet), fluorescence and refractive index. Conclusions: The developed andvalidated LC-MS/MS method for the determination of UDCA and related substances in raw material and in a suspension wasadvantageous since it required a minimum sample amount. In turn, it could be used as a stability indicating method.Fil: Boscolo, Oriana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Flor, Sabrina Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica. Cátedra de Química Analítica; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Dobrecky Ceciclia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Martinefski, Manuela Romina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica. Cátedra de Química Analítica; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Tripodi, Valeria Paula. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Lucangioli, Silvia Edith. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Anti Transglutaminase Antibodies Cause Ataxia in Mice

Background: Celiac disease (CD) is an autoimmune gastrointestinal disorder characterized by the presence of anti-transglutaminase 2 (TG2) and anti-gliadin antibodies. Amongst the neurological dysfunctions associated with CD, ataxia represents the most common one. Methods: We analyzed by immunohistochemistry, the anti-neural reactivity of the serum from 20 CD patients. To determine the role of anti-TG2 antibodies in ataxia, two anti-TG2 single chain variable fragments (scFv), isolated from a phage-display IgA antibody library, were characterized by immunohistochemistry and ELISA, and injected in mice to study their effects on motor coordination. We found that 75% of the CD patient population without evidence of neurological involvement, has circulating anti-neural IgA and/or IgG antibodies. Two anti-TG2 scFvs, cloned from one CD patient, stained blood vessels but only one reacted with neurons. This anti-TG2 antibody showed cross reactivity with the transglutaminase isozymes TG3 and TG6. Intraventricular injection of the anti-TG2 or the anti-TG2/3/6 cross-reactive scFv provoked transient, equally intensive ataxia in mice. Conclusion: The serum from CD patients contains anti-TG2, TG3 and TG6 antibodies that may potentially cause ataxia

Highly Sensitive Electrochemiluminescent Nanobiosensor for the Detection of Palytoxin

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Multidrug-resistant organisms in lung transplant: a narrative review

Purpose of review: The purpose of this narrative review is presenting the current knowledge of multidrug-resistant (MDR) pathogens in lung transplant recipients, considering both Gram-positive and Gram-negative bacteria. Recent findings: Overall prevalence of Gram-negative pathogens has increased remarkably (4.33/1000 recipient-days) in solid organ transplant recipients, while the prevalence of Gram-positive bacteria seems to be decreasing (0.20 cases/100 transplant-years). In lung transplant, the prevalence of postoperative infections due to MDR-GN bacteria has been assessed between 31 and 57%, and the incidence of carbapenem-resistant Enterobacterales is between 0.4 and 20%, with a related mortality up to 70%. MDR Pseudomonas aeruginosa is common in lung transplant recipients with cystic fibrosis and may contribute to bronchiolitis obliterans syndrome. The prevalence of MDR Gram-positive bacteria is around 30% (predominantly Methicillin-resistant Staphylococcus aureus and Coagulase-negative staphylococcus). Summary: Survival after lung transplant, although lower than in other SOT, is increasing and currently at 60% at 5 years. This review highlights the potential clinical and social burden of postoperative infections in lung transplant recipients, and confirmed that a PI due to MDR bacteria negatively affects survival. A prompt diagnosis, prevention and management of these MDR pathogens should remain the cornerstone for higher goals of care

Novel cathelicidins in horse leukocytes11Accession numbers: the nucleotide sequences of eCATH-1, eCATH-2 and eCATH-3 are deposited in the EMBL nucleotide sequence database under accession numbers AJ224927, AJ224928 and AJ224929.

AbstractCathelicidins are precursors of defense peptides of the innate immunity and are widespread in mammals. Their structure comprises a conserved prepropiece and an antimicrobial domain that is structurally varied both intra- and inter-species. We investigated the complexity of the cathelicidin family in horse by a reverse transcription-PCR-based cloning strategy of myeloid mRNA and by Southern and Western analyses. Three novel cathelicidin sequences were deduced from bone marrow mRNA and designated equine cathelicidins eCATH-1, eCATH-2 and eCATH-3. Putative antimicrobial domains of 26, 27 and 40 residues with no significant sequence homology to other peptides were inferred at the C-terminus of the sequences. Southern analysis of genomic DNA using a probe based on the cathelicidin-conserved propiece revealed a polymorphic DNA region with several hybridization-positive fragments and suggested the presence of additional genes. A null eCATH-1 allele was also demonstrated with a frequency of 0.71 in the horse population analyzed and low amounts of eCATH-1-specific mRNA were found in myeloid cells of gene-positive animals. A Western analysis using antibodies to synthetic eCATH peptides revealed the presence of eCATH-2 and eCATH-3 propeptides, but not of eCATH-1-related polypeptides, in horse neutrophil granules and in the secretions of phorbol myristate acetate-stimulated neutrophils. These results thus suggest that eCATH-2 and eCATH-3 are functional genes, whereas eCATH-1 is unable to encode a polypeptide

Formulation and Characterization of Ursodeoxycholic Acid Nanosuspension Based on Bottom-Up Technology and Box–Behnken Design Optimization

Background: Ursodeoxycholic acid (UDCA) is a therapeutic agent used for the treatment of cholestatic hepatobiliary diseases in pediatric patients. It is a bile acid that presents high lipophilicity, and it belongs to Class II of the Biopharmaceutical Classification System (BCS), which exhibits low water solubility and high intestinal permeability, which leads to poor oral absorption. The objective of this work was to design and optimize UDCA nanosuspensions by means of the precipitation-ultrasonication method to improve the solubility, dissolution, and oral bioavailability of UDCA. Methods: A three-level, three-factor Box–Behnken design was used to optimize formulation variables and obtain uniform, small-particle-size UDCA nanosuspensions. The independent variables were: stabilizer percentage (X1), amplitude (X2), and sonication time (X3), and the dependent variable was the particle size (Y1). In the precipitation–ultrasonication method, UDCA was dissolved in acetone:PEG 400 (1:1 v/v) and quickly incorporated into the antisolvent (pre-cooled aqueous dispersion of HPMC E-15 0.3%), by means of intense sonication at 50 W for 5 min, controlling temperature through an ice water bath. The lyophilization efficacy was evaluated by means of a cryoprotective efficacy test, working with 10% maltose at −80 °C. The nanosuspensions were characterized by dynamic light scattering (DLS), X-ray diffraction, and scanning electron microscopy (SEM). The physicochemical stability was determined at 25 °C and 4 °C at 7, 14, 30, and 60 days, and the UDCA content was analyzed via HPLC-UV. An in vitro dissolution assay and an oral bioavailability study were performed in male Wistar rats. Results: A significant impact was achieved in the optimized nanosuspension with 0.3% (stabilizer), 50 W (amplitude), and 5 min (sonication time), with a particle size of 352.4 nm, PDI of 0.11, and zeta potential of −4.30 mV. It presented adequate physicochemical stability throughout the study and the UDCA content was between 90% and 110%. In total, 86% of UDCA was dissolved in the in vitro dissolution test. The relative oral bioavailability was similar without significant statistical differences when comparing the lyophilized nanosuspension and the commercial tablet, the latter presenting a more erratic behavior. The pharmacokinetic parameters of the nanosuspension and the commercial tablet were Tmax (1.0 ± 0.9 h vs. 2.0 ± 0.8 h, respectively), Cmax (0.558 ± 0.118 vs. 0.366 ± 0.113 µM, respectively), ΔCmax (0.309 ± 0.099 vs. 0.232 ± 0.056, respectively), AUC (4.326 ± 0.471 vs. 2.188 ± 0.353 µg/mL.h, respectively, p 0–24h (2.261 ± 0.187 µg/mL.h vs. 1.924 ± 0.440 µg/mL.h, respectively). Conclusions: The developed nanosuspension presents an appropriate dosage and administration for pediatric patients. On the other hand, it exhibits an adequate absorption and UDCA oral bioavailability

Development and validation of a LC-UV Method Applied to the Quality Control of Ursodeoxycholic Acid in Raw Material and Pharmaceutical Formulations

A simple, fast, and sensitive HPLC method with UV detection has been developed for the quantitation of ursodeoxycholic acid (UDCA) in raw material and pharmaceutical formulation (suspension). Cromatographic conditions were: Symmetry-C18 column (150 mm x 4.6 mm, id; particle size 5 µm), 40 ˚C, 100 µL injection volume and UV detection at 200 nm. The flow rate was 1 ml/min using acetonitrile - phosphoric acid (pH 3.0; 0.15mM) (48:52) as mobile phase. The method was validated according to international guidelines (ICH guidelines) for specificity, linearity, LOD, LOQ, precision, accuracy, and robustness. The HPLC-UV method was found to be suitable for the quality control of UDCA raw material and pharmaceutical formulation.Fil: Boscolo, Oriana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Flor, Sabrina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica; ArgentinaFil: Dobrecky, Cecilia Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Salvo, Lucila. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Tripodi, Valeria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Lucangioli, Silvia Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; Argentin

Applications of Capillary Electrophoresis to Pharmaceutical and Biochemical Analysis

In the last decades, miniaturized separation techniques have rapidly gained popularity in different areas of analysis such as pharmaceutical, biopharmaceutical, clinical, biological, environmental, and forensics. The great advantages presented by the analytical miniaturized techniques, including high separation efficiency and resolution, rapid analysis and minimal consumption of reagents and samples, make them an attractive alternative to the conventional chromatographic methods.In this sense, capillary electrophoresis (CE) is a family of related techniques that employs narrow-bore capillaries to perform highly efficient separations from large to small molecules. Different modes are applied in CE. Capillary zone electrophoresis (CZE) using a simple buffer as electrolyte, is widely used for the analysis of inorganic and organic ions. Another CE mode is electrokinetic chromatography (EKC),in which the separation principle is based on the differential partition between the analytes and a pseudostationary phase as well as the migration behavior of the analytes. Several nanostructures are used as pseudostationary phases like micelles, microemulsion droplets, and polymers, increasing the selectivity and versatility of the analytical system.CE advantages with respect to other analytical techniques comprise very high resolution in short time of analysis, versatility, the possibility to analyze molecules without chromophore groups, simultaneous analysis of compounds with different hydrophobic characteristics, small sample volume, and low cost. Moreover, it is possible to adapt this technique to the analysis of numerous types of compounds like biological macromolecules, chiral compounds, inorganic ions, organic acids, DNA fragments and even whole cells and virus particles. An increasing number of CE applications are in progress in many clinical laboratories. As this technique employs small sample volumes, is ideal for the analysis of biological fluids in which the limited amount of sample represents a challenge. In pharmaceutical quality control, it is possible to determine active ingredients in the presence of related substances with different physicochemical characteristics, especially chiral impurities in the final products using the same analytical system with a relatively simple instrumental. Moreover, numerous applications are reported in the analysis of inorganic ions. Also, the determination of macromolecules such as polysaccharides, therapeutic proteins, and flavonoids present in plant extracts, biological and biopharmaceutical products may also be analyzed with this technique.In summary, CE has become an important analytical tool in the field of research, clinics and pharmaceutical industry offering a large number of applications, in biological, natural and pharmaceutical samples, as an alternative or complementary option to traditional analytical techniques to implement in the routine laboratory.Fil: Flor, Sabrina Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Contin, Mario Daniel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Martinefski, Manuela Romina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Dobrecky, Cecilia Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Cattalini, Juan Pablo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Boscolo, Oriana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Tripodi, Valeria Paula. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Lucangioli, Silvia Edith. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Harmful Dinoflagellate Ostreopsis cf. ovata Fukuyo: Detection of Ovatoxins in Field Samples and Cell Immunolocalization Using Antipalytoxin Antibodies

Ostreopsis cf. ovata, a benthic dinoflagellate often blooming along the Mediterranean coasts, has been associated with toxic events ranging from dyspnea to mild dermatitis. In late September 2009, an Ostreopsis cf. ovata bloom occurred in the Gulf of Trieste (Northern Adriatic Sea; Italy), causing pruritus and mild dermatitis in beachgoers. An integrated study was initiated to characterize Ostreopsis cells by light and confocal microscopy, PCR techniques, immunocytochemistry, and high resolution liquid chromatography\u2013mass spectrometry (HR LC-MS). The presence of Ostreopsis cf. ovata of the Atlantic/Mediterranean clade was unambiguously established by morphological and genetic analyses in field samples. Several palytoxin-like compounds (ovatoxin-a,-b,-c,-d,-e) were identified by HR LC-MS, ovatoxin-a being the most abundant (45\u201364 pg/cell). Surprisingly, no palytoxin was detected. For the first time, monoclonal and polyclonal antipalytoxin antibodies revealed the intracellular cytoplasmic localization of ovatoxins, suggesting their cross-reactivity with these antibodies. Since harmful dinoflagellates do not always produce toxins, the immunocytochemical localization of ovatoxins, although qualitative, can provide an early warning for toxic Ostreopsis cells before their massive diffusion and/or concentration in seafood