Solvent N-methylpyrrolidone Research Articles

Acute ®Confidor (imidacloprid-N-methyl pyrrolidone) insecticides intoxication with mimicking cholinergic syndrome

Confidor, consisting of two major components - imidacloprid and the solvent N-methyl pyrrolidone is a relatively new class of insecticide. Reports of acute overdose or adverse effects after human exposure have been few, despite wide usage. We report a case of acute confidor intoxication with mimicking cholinergic syndrome, the patient ultimately dying of nosocominal pneumonia. Patients ingesting large volumes of imidacloprid-N-methyl pyrrolidone insecticide formulations require close observation and supportive treatment.

Cyclosporin Nanoparticulate Lipospheres for Oral Administration

Cyclosporin is a first line immunosuppressive drug used to prevent transplant rejection and to treat autoimmune diseases. It is a hydrophobic cyclic peptide built from nonmammalian amino acids with low oral bioavailability. The aim of this study was to develop an oral delivery system for cyclosporin A (CyA) and investigate the effect of composition and particle size of the CyA lipid nanoparticles (lipospheres) on the oral bioavailability of this drug. Dispersible concentrated oil formulations that upon mixing in water spontaneously form a nanodispersion were developed. The concentrated oil formulations were clear solutions composed of the drug, a solid triglyceride, a water miscible organic solvent, and a mixture of surfactants and emulsifiers. The activity of the formulated cyclosporin was determined in vitro following the effect on the proliferation of T cells. The oral bioavailability was determined on humans following the cyclosporin blood levels after oral intake of formulated cyclosporin. Cyclosporin dispersion systems resulting in particle size of 25 to 400nm were prepared from acceptable pharmceutical components. The composition of the surfactants and emulsifiers, the lipid core component, and the amount and type of the water miscible organic solvent N-methylpyrrolidone (NMP) and alcohols had a strong effect on the particle size of the dispersions. All formulations were reproducible and stable at room temperature for at least 6 months, with full activity of cyclosporin retained. Human oral bioavaiability study indicated a correlation between the AUC and Cmax and the particle size of the dispersion. A Cmax of ∼1300 ng/mL was found after 2h of oral intake of four capsules, each loaded with 50mg cyclosporin. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1264–1270, 2004

Solvent Extraction of Aromatic Components from Lube-Oil Cut byN-methylpyrrolidone (NMP)

A method has been developed for the modeling of complex hydrocarbon mixtures which is based on the accurately simulated distillation gas chromatography analysis as well as the extended method of Ruzicka et al for making the model molecules. The method has been used for modeling of the complex mixture of the lube-oil cut SAE 10 in the aromatics extraction process with the solvent N-methylpyrrolidone (NMP) from the Tehran Refinery. To carry out the liquid-liquid equilibria calculations, the van der Waals surface and volume size parameters of the model molecules and NMP as well as their interaction parameters are required which they are calculated by the Bondi's group contribution method with the NMP molecule taken as a functional group according to the approach of Rahman et al. Solvent extraction process at two temperatures of 50 and 42 °C both at 1 atm have been carried out in a batch mixer-settler and the properties of resultant phases (extract and raffinate) have been determined by the precise measuring systems using the standard methods of ASTM and the well-known Riazi's equations. Finally, the results of the equilibrium calculations have been compared with the experimental data and good agreement was found.

A PROCEDURE FOR THE PRODUCTION OF ULTRA-PURE PRECURSORS FROM COAL FOR THE MANUFACTURE OF VALUE-ADDED CARBON PRODUCTS - PREPARATION OF AN EXTRACT

ABSTRACT Solvent extraction is a potential technique for the production of coal-derived extracts which may be suitable as precursors for value-added carbon products. At present. the development of new and non-conventional markets for coal has resulted in the exploration of new applications such as slurry fuels, coal-based graphites, carbon-carbon composites and carbon anodes. However, for carbon products to perform acceptably in such applications, the ash content of the precursor must be less than 0.1%. Although, work to produce a low-ash (ca. 0.2%), low-sulfur coal-derivcd material had begun about a decade ago through solvent extraction using the solvent NMP (N-methyl-2-pyrrolidone), it was practically impossible to produce a coal-dcrivcd extract containing less than 0.2% ash. This is due to the presence of ultra-fine mineral matter particles and solvent soluble inorganic species. The principal objective of the present work was to investigate techniques for the separation of the coal-derived extract from...

Measurement of phase equilibrium in multicomponent systems of aromatics with n-methylpyrrolidone and predictions with unifac

Liquid—liquid equilibrium (LLE) of five binary and five ternary systems containing the solvent N-methylpyrrolidone (NMP) with different paraffins and aromatics were measured. The data presented in this work were used in the estimation of UNIFAC model interaction parameters between NMP and the main groups: CH 2, ACCH 2, ACH and CHNA. The estimated interaction parameters of these groups were used in conjunction with other interaction parameters presented in the literature to predict the phase equilibrium of NMP with a synthetic multicomponent system composed of paraffins, condensed naphthenes, monoaromatics and diaromatics. The results compare favourably with the experimental data measured in this work.