Development and evaluation of orally disintegrating tablets (ODTs) containing Ibuprofen granules prepared by hot melt extrusion

In the current study Ibuprofen was embedded in a methacrylate copolymer (Eudragit^® EPO) matrix to produce solid dispersions by hot-melt extrusion (HME) processing. The obtained granules were incorporated in orally disintegrating tablets (ODTs). The tablets were developed by varying the ratio of superdisintegrants such as sodium croscarmellose and crosslinked polyvinylpyrrolidone grades while a direct compression process was used to compress the ODTs under various compaction forces to optimize tablet robustness. The properties of the compressed tablets which included porosity, hardness, friability and dissolution profiles were further evaluated and compared with Nurofen^® Meltlet ODTs. The taste and sensory evaluation in human volunteers demonstrated excellence in masking the bitter active and improved tablet palatability.     

Rapid identification and semi-quantitative determination of polymer additives by desorption electrospray ionization/time-of-flight mass spectrometry

A fast and simple method for the direct qualitative and semi-quantitative determination of a set of four polymer additives in plastic samples by desorption electrospray ionization time-of-flight mass spectrometry (DESI-TOF-MS) is presented. After evaluation of crucial DESI parameters such as composition of spray solutions and spray voltages, a series of lab-made polypropylene samples containing Chimassorb 81 (2-hydroxy-4-n-octoxybenzophenone), Tinuvin 328 (2-(2-hydroxy-3, 5-ditert-pentylphenyl)-benzotriazole), Tinuvin 326 (2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chloro benzotriazole), and Tinuvin 770 (bis(2,2,6,6,-tetramethyl-4-piperidyl)sebaceate) in concentrations between 0.02% and 0.2% were analyzed, resulting in calibration graphs with R ² better than 0.994. To demonstrate the applicability of the developed method for the investigation of real samples, liners for in-ground swimming pools and polypropylene granules were analyzed with respect to their content in the selected polymer additives. Two alternative methods, both well established in the fields of polymer additive analysis, namely HPLC with UV detection (after previous extraction) and thermodesorption gas chromatography/mass spectrometry have been employed for evaluation of the results from the DESI experiments.     

Quantitative determination of 43 common drugs and drugs of abuse in human serum by HPLC-MS/MS

An analytical procedure for the simultaneous determination in human serum of 43 common drugs of abuse and their metabolites belonging to the different chemical and toxicological classes of amphetamines, benzodiazepines, dibenzazepines, cocaine, lysergic acid diethylamide, opioids, phencyclidine, tricyclic antidepressants, and zolpidem, using 33 deuterated standards, is presented. The sample treatment was developed to be a very simple protein precipitation and filtration. All analyses were performed with a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry in positive ionization mode. All analytes were calibrated up to 550 μg/L. The limit of detection ranged from 0.6 ng/mL (EDDP) to 13.7 ng/mL (flunitrazepam). The method has been validated according to the guidelines of the Gesellschaft für Toxikologische und Forensische Chemie, using three multiple reaction mode (MRM) transitions and retention time for positive compound identification, instead of two MRMs, in anticipation of the new guidelines for January 2011.     

Ionic Liquids: New Perspectives for Inorganic Synthesis?

Ionic liquids are credited with a number of unusual properties. These include a low vapor pressure, a wide liquid‐phase range, weakly coordinating properties, and a high thermal/chemical stability. These properties are certainly of great interest for inorganic synthesis and the creation of novel inorganic compounds. On the other hand, the synthesis repertoire for preparing inorganic compounds has always been broad, ranging from syntheses in solutions and melts to solid‐state reactions, and from crystal growth in the gas phase to high‐pressure syntheses. What new aspects can ionic liquids then add to the synthesis of inorganic compounds? This Minireview uses some early examples to show that the use of ionic liquids indeed provides access to unusual inorganic compounds.     

Postbuckling of imperfect rectangular composite plates under inplane shear closed-form approximate solutions

In this paper, the postbuckling behavior of rectangular orthotropic laminated composite plates with initial imperfections under inplane shear load is investigated in a closed-form analytical manner. The plates under consideration are assumed to be infinitely long in the longitudinal direction. At the longitudinal edges, two different sets of boundary conditions are considered, specifically 1) simply supported edges and 2) fully clamped edges. Using Timoshenko-type shape functions for both the initial bifurcational buckling analysis and the subsequent Marguerre-type postbuckling studies, closed-form analytical solutions for the buckling loads and for the postbuckling state variables are derived. A comparison with geometrically non-linear finite element computations shows that the derived analysis approaches are suitable for postbuckling studies in load ranges not too far beyond bifurcational buckling as they are currently relevant for e.g., composite airframe structural analysis and design. Due to their strictly closed-form analytical nature, the presented analysis methods can be used conveniently in engineering practice for all application purposes where computational time is a crucial factor, especially for preliminary analysis and design or optimization procedures.     

An Approximate Distribution for the Maximum Order Complexity

In this paper we give an approximate probability distribution for the maximum order complexity of a random binary sequence. This enables the development of statistical tests based on maximum order complexity for the testing of a binary sequence generator. These tests are analogous to those based on linear complexity.     

Nachweis der salpetrigen S?ure im Trinkwasser

Ohne Zusammenfassung