Stability-indicating HPLC-DAD/UV-ESI/MS impurity profiling of the anti-malarial drug lumefantrine

<p>Abstract</p> <p>Background</p> <p>Lumefantrine (benflumetol) is a fluorene derivative belonging to the aryl amino alcohol class of anti-malarial drugs and is commercially available in fixed combination products with β-artemether. Impurity characterization of such drugs, which are widely consumed in tropical countries for malaria control programmes, is of paramount importance. However, until now, no exhaustive impurity profile of lumefantrine has been established, encompassing process-related and degradation impurities in active pharmaceutical ingredients (APIs) and finished pharmaceutical products (FPPs).</p> <p>Methods</p> <p>Using HPLC-DAD/UV-ESI/ion trap/MS, a comprehensive impurity profile was established based upon analysis of market samples as well as stress, accelerated and long-term stability results. <it>In-silico </it>toxicological predictions for these lumefantrine related impurities were made using Toxtree^®and Derek^®.</p> <p>Results</p> <p>Several new impurities are identified, of which the desbenzylketo derivative (DBK) is proposed as a new specified degradant. DBK and the remaining unspecified lumefantrine related impurities are predicted, using Toxtree^®and Derek^®, to have a toxicity risk comparable to the toxicity risk of the API lumefantrine itself.</p> <p>Conclusions</p> <p>From unstressed, stressed and accelerated stability samples of lumefantrine API and FPPs, nine compounds were detected and characterized to be lumefantrine related impurities. One new lumefantrine related compound, DBK, was identified and characterized as a specified degradation impurity of lumefantrine in real market samples (FPPs). The <it>in-silico </it>toxicological investigation (Toxtree^®and Derek^®) indicated overall a toxicity risk for lumefantrine related impurities comparable to that of the API lumefantrine itself.</p

Acute phase response in two consecutive experimentally induced E. coli intramammary infections in dairy cows

<p>Abstract</p> <p>Background</p> <p>Acute phase proteins haptoglobin (Hp), serum amyloid A (SAA) and lipopolysaccharide binding protein (LBP) have suggested to be suitable inflammatory markers for bovine mastitis. The aim of the study was to investigate acute phase markers along with clinical parameters in two consecutive intramammary challenges with <it>Escherichia coli </it>and to evaluate the possible carry-over effect when same animals are used in an experimental model.</p> <p>Methods</p> <p>Mastitis was induced with a dose of 1500 cfu of <it>E. coli </it>in one quarter of six cows and inoculation repeated in another quarter after an interval of 14 days. Concentrations of acute phase proteins haptoglobin (Hp), serum amyloid A (SAA) and lipopolysaccharide binding protein (LBP) were determined in serum and milk.</p> <p>Results</p> <p>In both challenges all cows became infected and developed clinical mastitis within 12 hours of inoculation. Clinical disease and acute phase response was generally milder in the second challenge. Concentrations of SAA in milk started to increase 12 hours after inoculation and peaked at 60 hours after the first challenge and at 44 hours after the second challenge. Concentrations of SAA in serum increased more slowly and peaked at the same times as in milk; concentrations in serum were about one third of those in milk. Hp started to increase in milk similarly and peaked at 36–44 hours. In serum, the concentration of Hp peaked at 60–68 hours and was twice as high as in milk. LBP concentrations in milk and serum started to increase after 12 hours and peaked at 36 hours, being higher in milk. The concentrations of acute phase proteins in serum and milk in the <it>E. coli </it>infection model were much higher than those recorded in experiments using Gram-positive pathogens, indicating the severe inflammation induced by <it>E. coli</it>.</p> <p>Conclusion</p> <p>Acute phase proteins would be useful parameters as mastitis indicators and to assess the severity of mastitis. If repeated experimental intramammary induction of the same animals with <it>E. coli </it>is used in cross-over studies, the interval between challenges should be longer than 2 weeks, due to the carry-over effect from the first infection.</p

Reactive oxygen species generation by bovine blood neutrophils with different CXCR1 (IL8RA) genotype following Interleukin-8 incubation

Background: Associations between polymorphisms in the bovine CXCR1 gene, encoding the chemokine (C-X-C motif) receptor 1 (IL8RA), and neutrophil traits and mastitis have been described. In the present study, blood neutrophils were isolated from 20 early lactating heifers with different CXCR1 genotype at position 735 or 980. The cells were incubated with different concentrations of recombinant bovine IL-8 (rbIL-8) for 2 or 6 h and stimulated with phorbol 12-myristate 13-acetate (PMA) or opsonized zymosan particles (OZP). Potential association between CXCR1 genotype and production of reactive oxygen species (ROS) was studied. Results: Although on single nucleotide polymorphisms (SNPs) may potentially affect CXCR1 function, SNPs c.735C > G and c.980A > G showed no association with ROS production with or without incubation of rbIL-8. Neutrophils incubated with rbIL-8 for 2 or 6 h showed higher PMA- and lower OZP-induced ROS production compared to control without rbIL-8. Conclusions: In the present study no association could be detected between superoxide production by isolated bovine neutrophils during early lactation and CXCR1 gene polymorphism. IL-8 showed to possess inhibitory effects on ROS generation in bovine neutrophils

Escherichia coli mastitis in periparturient cows: An overview of ten years of research on the role of neutrophil leukocytes in local and systemic reactions.

Mastitis is determined by environmental factors, cow related factors and pathogens, During the last ten years many insights have been gathered that lead to the suggestion that neutrophil leukocytes play an important role during acute coliform mastitis in dairy cows around the time of parturition. Upon the invasion of micro-organisms in the mammary gland, peripheral blood Leukocytes migrate into the udder in large numbers, Opsonization, phagocytosis and intracellular killing are meant to eliminate the hazardous mastitis pathogens, In this review, the qualitative and quantitative aspects of these cell functions before and during experimentally induced infections are discussed along with the local and the systemic reactions that are involved in this process