fumarates and acetonitrile

A simple, unique and selective HPLC-PDA method was developed and validated for the simultaneous estimation of aliskiren (ALS) and amlodipine (AML) in human plasma. Extraction of the sample was accomplished by protein precipitation. Plasma proteins were precipitated by employing acetonitrile containing hydrochlorothiazide as internal standard. The compounds were analyzed by HPLC by using PDA detector on a Hibar C18 (250 × 4.6 mm) column with a mobile phase comprising acetonitrile and phosphate buffer (pH 4.2 and 25 mm; 60:40 v/v) with a flow rate of 0.8 mL/min. Different sample pretreatment techniques were evaluated but protein precipitation was found to be satisfactory, offering good recovery values of 97.11-98.45% for ALS and 97.5-99.12% for AML. The within-day precisions for ALS were 96.66, 99.16 and 99.41% at 90, 240 and 480 ng/mL, respectively, and for AML they were 97.27, 99.54 and 99.31% at 3.3, 8.8 and 17.6 ng/mL, respectively. The between-day precisions for ALS were 96.66, 99.16 and 99.41% at 90, 240 and 480 ng/mL, respectively and the between-day precisions for AML were 98.18, 99.20 and 99.40% at 3.3, 8.8 and 17.6 ng/mL, respectively. The limit of quantitation was 30 and 1.0 ng/mL for ALS and AML respectively. Different constituents of plasma proteins did not interfere with the absolute recovery of ALS and AML.

Topics: Acetonitriles; Amides; Amlodipine; Chemical Precipitation; Chromatography, High Pressure Liquid; Drug Stability; Fumarates; Humans; Hydrochlorothiazide; Limit of Detection; Sensitivity and Specificity

The Drosophila ZESTE system was used to monitor the induction of sex chromosome aneuploidy following inhalation exposure of adult females to four nitriles: acetonitrile, propionitrile, acrylonitrile and fumaronitrile. Acetonitrile and propionitrile were highly effective aneuploidogens, inducing both chromosome loss and chromosome gain following brief exposures to low concentrations of these chemicals, and these nitriles also induced rapid paralysis. Acrylonitrile-induced chromosome loss only but did not induce paralysis. Fumaronitrile, in contrast with the results reported in yeast, was ineffective in inducing chromosome loss or gain. Virtually all exceptional offspring induced by acetonitrile and propionitrile were recovered in the first sampled eggs, corresponding to treated mature oocytes. Additionally, the time interval between treatment and sampling was shown to be important, suggesting rapid loss or detoxification of the nitriles. Genetic analysis demonstrated that most aneuploids resulted from induced segregation errors during the first division of meiosis. Cold treatments were found to be ineffective in enhancing the effects of acetonitrile, suggesting important differences between the Drosophila and yeast aneuploidy detection systems. Possible mechanisms by which nitriles may disrupt chromosome segregation in Drosophila oocytes are considered.

Topics: Acetonitriles; Acrylonitrile; Administration, Inhalation; Age Factors; Aneuploidy; Animals; Dose-Response Relationship, Drug; Drosophila melanogaster; Female; Fumarates; Mutagens; Nitriles; Nondisjunction, Genetic; Sex Chromosomes; Temperature; Time Factors

Two aliphatic nitriles, acetonitrile and fumaronitrile were tested for their genotoxic potential in three mutagenicity test systems: the Salmonella/microsome-assay, an assay using Saccharomyces cerevisiae (strain D7), and the bone marrow micronucleus test. Both compounds were tested with and without metabolic activation in the yeast and the bacterial test systems using S9 preparations from phenobarbitone-pretreated and autoinduced rats. Autoinduction was performed by chronic (7 days) application of a dose equivalent to a 5% oral LD50-value of the respective compound. With yeast strain D7 both nitriles induced low levels of gene conversion in the presence of phenobarbitone-induced liver homogenate. An increase in the number of ile+-revertants was not detectable under any condition. Neither of the compounds showed mutagenic activity in the Ames test with or without metabolic activation. A weak positive effect of acetonitrile could be detected in the micronucleus test 24 h after i.p.-injection of the compound using a dose of 60% LD50. Fumaronitrile showed positive results with a 50% LD50 dose 48 h after administration to mice not preinduced. After 1 week of autoinduction these effects did not appear anymore, with the exception of acetonitrile 72 h after application of a dose amounting to 60% of the oral LD50-value.

Topics: Acetonitriles; Animals; Female; Fumarates; Male; Mice; Mice, Inbred Strains; Micronucleus Tests; Mixed Function Oxygenases; Mutagenicity Tests; Mutagens; Saccharomyces cerevisiae; Salmonella typhimurium