tretinoin and acetonitrile

tretinoin has been researched along with acetonitrile* in 7 studies

Other Studies

7 other study(ies) available for tretinoin and acetonitrile

ArticleYear
Analysis of fenretinide and its metabolites in human plasma by liquid chromatography-tandem mass spectrometry and its application to clinical pharmacokinetics.
    Journal of pharmaceutical and biomedical analysis, 2017, Jan-05, Volume: 132

    A simple and accurate high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of N-(4-hydroxyphenyl)retinamide (fenretinide, 4-HPR) and its metabolites, 4-oxo-N-(4-hydroxyphenyl)retinamide (4-oxo-4-HPR) and N-(4-methoxyphenyl)retinamide (4-MPR), in human plasma. Plasma samples were prepared using protein precipitation with ethanol. Chromatographic separation of the three analytes and N-(4-ethoxyphenyl)retinamide (4-EPR), an internal standard, was achieved on a Zorbax SB-C18 column (3.5μm, 50×2.1mm) using gradient elution with the mobile phase of 0.1% formic acid in water and acetonitrile (pH* 2.4) at a flow rate of 0.5mL/min. Electrospray ionization (ESI) mass spectrometry was operated in the positive ion mode with multiple reaction monitoring (MRM). The calibration curves obtained were linear over the concentration range of 0.2-50ng/mL with a lower limit of quantification of 0.2ng/mL. The relative standard deviation of intra-day and inter-day precision was below 7.64%, and the accuracy ranged from 94.92 to 105.43%. The extraction recoveries were found to be higher than 90.39% and no matrix effect was observed. The analytes were stable for the durations of the stability studies. The validated method was successfully applied to the analyses of the pharmacokinetic study for patients treated with 4-HPR in a clinical trial.

    Topics: Acetonitriles; Algorithms; Chromatography, Liquid; Clinical Trials, Phase I as Topic; Fenretinide; Humans; Hydrogen-Ion Concentration; Ions; Limit of Detection; Mass Spectrometry; Neuroblastoma; Quality Control; Reproducibility of Results; Spectrometry, Mass, Electrospray Ionization; Temperature; Tretinoin; Water

2017
Solution and gas-phase acidities of all-trans (all-E) retinoic acid: an experimental and computational study.
    Chemistry (Weinheim an der Bergstrasse, Germany), 2015, Jul-27, Volume: 21, Issue:31

    Retinoic acid is of fundamental biological importance. Its acidity was determined in the gas phase and in acetonitrile solution by means of mass spectrometry and UV/Vis spectrophotometry, respectively. The intrinsic acidity is slightly higher than that of benzoic acid. In solution, the situation is opposite. The experimental systems were described theoretically applying quantum chemical methods (wave function theory and density functional theory). This allowed the determination of the molecular structure of the acid and its conjugate base, both in vacuo and in solution, and for computational estimates of its acidity in both phases.

    Topics: Acetonitriles; Acids; Gases; Models, Molecular; Quantum Theory; Solutions; Thermodynamics; Tretinoin

2015
Matrix segregation as the major cause for sample inhomogeneity in MALDI dried droplet spots.
    Journal of the American Society for Mass Spectrometry, 2014, Volume: 25, Issue:8

    The segregation in dried droplet MALDI sample spots was analyzed with regard to the matrix-to-sample ratio using optical microscopy, MALDI imaging mass spectrometry (MALDI MSI) and IR imaging spectroscopy. In this context, different polymer/matrix/solvent systems usually applied in the analysis of synthetic polymers were investigated. The use of typical matrix concentrations (10 mg mL⁻¹) in almost every case resulted in ring patterns, whereas higher concentrated matrix solutions always led to homogeneous sample spot layers. The data revealed that segregation is predominantly caused by matrix transport in the drying droplet, whereas polymer segregation seems to be only secondary.

    Topics: Acetonitriles; Electrochemical Techniques; Furans; Gentisates; Membranes, Artificial; Microscopy; Models, Molecular; Molecular Weight; Nitriles; Optical Imaging; Polyethylene Glycols; Polymethyl Methacrylate; Polystyrenes; Reproducibility of Results; Solvents; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Spectrophotometry, Infrared; Tretinoin; Volatilization

2014
Isotropic magnetic shielding constants of retinal derivatives in aprotic and protic solvents.
    The Journal of chemical physics, 2013, Sep-07, Volume: 139, Issue:9

    We investigate the nuclear isotropic shielding constants σ((13)C) and σ((17)O) of isomers of retinoic acid and retinal in gas-phase and in chloroform, acetonitrile, methanol, and water solutions via Monte Carlo simulation and quantum mechanics calculations using the GIAO-B3LYP∕6-311++G(2d,2p) approach. Electronic solute polarization effects due to protic and aprotic solvents are included iteratively and play an important role in the quantitative determination of oxygen shielding constants. Our MP2∕6-31G+(d) results show substantial increases of the dipole moment of both retinal derivatives in solution as compared with the gas-phase results (between 22% and 26% in chloroform and between 55% and 99% in water). For the oxygen atoms the influence of the solute polarization is mild for σ((17)O) of hydroxyl group, even in protic solvents, but it is particularly important for σ((17)O) of carbonyl group. For the latter, there is a sizable increase in the magnitude with increasing solvent polarity. For the carbon atoms, the solvent effects on the σ((13)C) values are in general small, being more appreciable in carbon atoms of the polyene chain than in the carbon atoms of the β-ionone ring and methyl groups. The results also show that isomeric changes on the backbones of the polyene chains have marked influence on the (13)C chemical shifts of carbon atoms near to the structural distortions, in good agreement with the experimental results measured in solution.

    Topics: Acetonitriles; Carbon Isotopes; Chloroform; Magnetic Fields; Methanol; Molecular Dynamics Simulation; Monte Carlo Method; Oxygen Isotopes; Quantum Theory; Retinaldehyde; Solvents; Tretinoin; Water

2013
A rapid HPLC method for simultaneous determination of tretinoin and isotretinoin in dermatological formulations.
    Journal of pharmaceutical and biomedical analysis, 2007, Feb-19, Volume: 43, Issue:3

    A rapid method using an isocratic high-pressure liquid chromatography and UV detection for determination of both all-trans retinoic acid (tretinoin) and 13-cis retinoic acid (isotretinoin) in dermatological preparations is presented. Tretinoin and isotretinoin samples were extracted with acetonitrile by a procedure that can be completed in less than 10 min. Subsequent separation and quantification of amounts as low as 10 pmol was accomplished in less than 15 min using reversed-phase HPLC with isocratic elution with 0.01% trifluoroacetic acid (TFA)/acetonitrile (15:85, v/v). Validation experiments confirmed the precision and accuracy of the method. When applied to commercial tretinoin samples, recoveries of 104.9% for cream formulations and 107.7% for gel formulations were obtained. Application of the method for analysis of a tretinoin cream exposed to solar simulated light (SSL) demonstrated detection of the major photoisomerization product isotretinoin as well as 9-cis retinoic acid, demonstrating the utility of the method for studies of tretinoin photostability. The method should also facilitate studies of the formulation compatibility and photocompatibility of tretinoin with agents that may improve its clinical tolerability.

    Topics: Acetonitriles; Chemistry, Pharmaceutical; Chromatography, High Pressure Liquid; Dermatologic Agents; Drug Incompatibility; Drug Stability; Gels; Isotretinoin; Keratolytic Agents; Ointments; Photochemistry; Quality Control; Regression Analysis; Reproducibility of Results; Spectrophotometry, Ultraviolet; Sunlight; Tretinoin; Trifluoroacetic Acid

2007
Quantitative high-performance liquid chromatographic determination of retinoids in human serum using on-line solid-phase extraction and column switching. Determination of 9-cis-retinoic acid, 13-cis-retinoic acid, all-trans-retinoic acid, 4-oxo-all-trans-
    Journal of chromatography. B, Biomedical sciences and applications, 1997, Mar-28, Volume: 691, Issue:1

    A fully automated isocratic high-performance liquid chromatographic method for the determination of 9-cis-retinoic acid, 13-cis-retinoic acid, all-trans-retinoic acid, 4-oxo-13-cis-retinoic acid and 4-oxo-all-trans-retinoic acid, has been developed using on-line solid-phase extraction and a column switching technique allowing clean-up and pre-concentration in a single step. A 500-microliter sample of serum was diluted with 750 microliters of a solution containing 20% acetonitrile and the internal standard 9,10-dimethylanthracene. About 1000 microliters of this mixture was injected on a 20 x 4.6 mm I.D. poly ether ether ketone (PEEK) pre-column with titanium frits packed with Bondapak C18, 37-53 microns, 300 A particles. Proteins and very polar compounds were washed out to waste, from the pre-column, with 0.05% trifluoroacetic acid (TFA)-acetonitrile (8.5:1.5, v/v). More than 200 aliquots of diluted serum could be injected on this pre-column before elevated back-pressure enforces replacement. Components retained on the pre-column were backflushed to the analytical column for separation and detection at 360 nm. Baseline separation was achieved using a single 250 x 4.6 mm I.D. Suplex pKb-100 column and a mobile phase containing 69:10:2:16:3 (v/v) of acetonitrile-methanol-n-butanol-2% ammonium acetate-glacial acetic acid. A total time of analysis of less than 30 min, including sample preparation, was achieved. Recoveries were in the range of 79-86%. The limit of detection was 1-7 ng/ml serum and the precision, in the concentration range 20-1000 ng/ml, was between 1.3 and 4.5% for all five compounds. The method was applied for the analysis of human serum after oral administration of 60 mg Roaccutan. The method is well suited for pharmacological studies, while the endogenous levels of some retinoic acid isomers are below the limit of quantitation.

    Topics: Acetonitriles; Alitretinoin; Autoanalysis; Chromatography, High Pressure Liquid; Drug Stability; Humans; Isotretinoin; Linear Models; Reproducibility of Results; Retinoids; Sensitivity and Specificity; Tretinoin; Trifluoroacetic Acid

1997
Simultaneous determination of 13-cis- and all-trans-retinoic acids and retinol in human serum by high-performance liquid chromatography.
    Journal of chromatography. B, Biomedical applications, 1994, Jul-01, Volume: 657, Issue:1

    A simple and accurate method was developed for the simultaneous determination of 13-cis- and all-trans-retinoic acid (13cRA, tRA), and retinol (ROH) in human serum using isocratic high-performance liquid chromatography (HPLC). The serum sample (0.2 ml) was diluted with 2 ml of acetonitrile-100 mM ammonium acetate (1:3, v/v), pH 5.5, and extracted with 5 ml of n-hexane. The extract was analyzed on an ODS column with a mobile phase consisting of 70 vols. of acetonitrile-methanol (2:1) and 30 vols. of 100 mM ammonium acetate, pH 7.0, at 50 degrees C. The retinoids were detected at 340 nm. Average recoveries were 88.4% for 13cRA, 82.5% for tRA at fortification levels of 5, 10 and 25 ng/ml, and 84.8% for ROH at 550 ng/ml. Within-day precision for normal human serum samples was 4.7% for 13cRA, 11.9% for tRA and 3.7% for ROH, and between-day precision was 10.4%, 14.2% and 4.7%, respectively. The limit of determination was 0.5 ng/ml in serum for the RAs. Mean concentration in 20 human sera was found to be 1.80 ng/ml for 13cRA, 1.77 ng/ml for tRA, and 487 ng/ml for ROH.

    Topics: Acetates; Acetonitriles; Chromatography, High Pressure Liquid; Hexanes; Humans; Hydrogen-Ion Concentration; Methanol; Reference Values; Reproducibility of Results; Sensitivity and Specificity; Tretinoin; Vitamin A

1994