Search results for "Pharmaceutical Preparation"
showing 10 items of 213 documents
Sequential window acquisition of all theoretical fragments versus information dependent acquisition for suspected-screening of pharmaceuticals in sed…
2019
The aquatic ecosystems are dynamic environments often affected directly or indirectly by a myriad of anthropogenic contaminants that need to be properly identified. In this study, liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QqTOF-MS) suspected-screening was applied to mussels and riverine sediment both, non-spiked and spiked with a mixture of 32 pharmaceuticals. Three data acquisition methods –sequential window acquisition of all theoretical fragment-ion spectra (SWATH), in fix (FSWATH) and variable (VSWATH) window modes and Information Dependent Acquisition (IDA)– were compared to determine the most suitable acquisition technique. The results obtained in the spike…
Low Grade Inflammation as a Common Pathogenetic Denominator in Age-Related Diseases: Novel Drug Targets for Anti-Ageing Strategies and Successful Age…
2010
Nowadays, people are living much longer than they used to do, however they are not free from ageing. Ageing, an inexorable intrinsic process that affects all cells, tissues, organs and individuals, is a post-maturational process that, due to a diminished homeostasis and increased organism frailty, causes a reduction of the response to environmental stimuli and, in general, is associated to an increased predisposition to illness and death. However, the high incidence of death due to infectious, cardiovascular and cancer diseases underlies a common feature in these pathologies that is represented by dysregulation of both instructive and innate immunity. Several studies show that a low-grade s…
Recent applications of flow-injection and sequential-injection analysis techniques to chemiluminescence determination of pharmaceuticals
2007
Abstract A review is presented on the state of the art of the chemiluminescence analysis of pharmaceuticals by the two most relevant automated controlled-flow methodologies—flow-injection analysis (FIA) and sequential-injection analysis (SIA). The current chemiluminometric applications of FIA and SIA in pharmaceutical analysis are discussed with special emphasis on the analytical figures of merit and sample matrix characteristics. The review involving 211 references and covering papers published between 2001 and 2006 is divided into several sections according to the fundamental types of chemiluminescence systems employed.
A mathematical approach to predicting the percutaneous absorption enhancing effect of sodium lauryl sulphate.
2003
A study has been made of the effect of sodium lauryl sulphate (SLS) at several concentrations from 0.24 to 5% (w/w) on skin permeability. Seven model drugs were selected for this study on the basis of their lipophilicity as represented by their logP(oct) values (from -0.95 to 4.2). Skin pre-treatment with aqueous solutions of SLS does not increase the permeability coefficient of the most lipophilic compounds (logP(oct)> or =3). For the other compounds assayed the increase in the permeability coefficients depends on the concentration of SLS used in the skin pre-treatment, and on the lipophilicity of the compounds tested.The correlation between the inverse of SLS efficacy as an enhancer (1/ER…
LC of high to moderately polar basic drugs in urine with water and detergent, and direct injection
2016
Background: Micellar LC was first proposed as a ‘green’ mode using mobile phases of water and surfactant. However, in most procedures a small amount of organic solvent is required to decrease the retention to convenient values. Results & methodology: Mixed micellar mobile phases prepared with both cationic (sodium dodecyl sulphate) and nonionic surfactant (Brij-35) modulate the retention of high to moderately polar basic drugs to practical times, eliminating the need of organic solvent. While the mobile phase is continuously recycled through the system, the stationary phase performance is maintained after repetitive injection of the samples. Discussion & conclusion: Through an exte…
Dual mixed-mode poly (vinylpyridine-co-methacrylic acid-co-ethylene glycol dimethacrylate)-based sorbent for acidic and basic drug extraction from or…
2021
Abstract In this study, a dual mixed-mode polymer sorbent was prepared via one-step thermally initiated polymerization of 4-vinylpyridine (VP), methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) for the solid-phase extraction (SPE) of basic and acidic drugs. The use of VP and MAA as ionizable functional monomers allowed the tailoring of ion-exchange and hydrophobic features of the polymer. The obtained polymer was characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Next, the retention behavior of dual mixed-mode polymer towards basic and acidic drugs was investigated. Moreover, the practical capability of this novel material was tested f…
Preconcentration of emerging contaminants in environmental water samples by using silica supported Fe3O4 magnetic nanoparticles for improving mass de…
2011
A magnetic material based on Fe(3)O(4) magnetic nanoparticles incorporated in a silica matrix by using a sol-gel procedure has been used to extract and preconcentrate emerging contaminants such as acetylsalicylic acid, acetaminophen, diclofenac and ibuprofen from environmental water samples prior to the analysis with Capillary LC-MS. The use of the proposed silica supported Fe(3)O(4) magnetic nanoparticles enables surfactant free extracts for the analysis with MS detection without interferences in the ionisation step. Under the optimum conditions, we demonstrated the reusability of the magnetic sorbent material during 20 uses without loss in the extraction efficiency. In addition, no cleanu…
The role of the dual nature of ionic liquids in the reversed-phase liquid chromatographic separation of basic drugs.
2010
The cationic nature of basic drugs gives rise to broad asymmetrical chromatographic peaks with conventional C18 columns and hydro-organic mixtures, due to the ionic interaction of the positively charged solutes with the free silanol groups on the alkyl-bonded reversed-phase packing. Ionic liquids (ILs) have recently attracted some attention to reduce this undesirable silanol activity. ILs are dual modifiers (with a cationic and anionic character), which means that both cation and anion can be adsorbed on the stationary phase, giving rise to interesting interactions with the anionic free silanols and the cationic basic drugs. A comparative study of the performance of four imidazolium-based I…
Time-Gated Raman Spectroscopy for Quantitative Determination of Solid-State Forms of Fluorescent Pharmaceuticals
2018
Raman spectroscopy is widely used for quantitative pharmaceutical analysis, but a common obstacle to its use is sample fluorescence masking the Raman signal. Time-gating provides an instrument-based method for rejecting fluorescence through temporal resolution of the spectral signal and allows Raman spectra of fluorescent materials to be obtained. An additional practical advantage is that analysis is possible in ambient lighting. This study assesses the efficacy of time-gated Raman spectroscopy for the quantitative measurement of fluorescent pharmaceuticals. Time-gated Raman spectroscopy with a 128 X (2) X 4 CMOS SPAD detector was applied for quantitative analysis of ternary mixtures of sol…
Vertical distribution of pharmaceuticals in lake sediments-citalopram as potential chemomarker
2012
The use of pharmaceuticals has increased enormously over the last few decades and serious concerns about their environmental fate and effects have arisen. Thus far, there is little knowledge about the historical pollution of the environment by pharmaceuticals. In the present study, sediment columns from three lake sites adjacent to wastewater treatment plants were collected, further divided in 2- or 2.5-cm slices, and analyzed for 15 pharmaceuticals by liquid chromatography-tandem mass spectrometry. In addition, sediment columns were historically interpreted by analyzing fecal sterols (coprostanol and cholesterol) as well as organic material and organic carbon. Several pharmaceuticals were …