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Determination of Nitroglycerin and Ethylene Glycol Dinitrate (Nitroglycol) in Air
Published in James P. Lodge, Methods of Air Sampling and Analysis, 2017
The use of pure NG and pure EGDN as reference standards is considered to be impractical for general application because of the safety hazard and the lack of availability of the compounds in pure form. In the course of the development of this method, several reference standards were obtained from the quality control laboratories of manufacturers of nitrate ester products. These materials included the following: A material called “Nitroglycerin Lactose Trituration” was provided by Eli Lilly and Company, Indianapolis, Indiana. This material is used for quality control of sublingual nitroglycerin tablets that are manufactured for medicinal use and has a stated nitroglycerin content. It consists of nitroglycerin dispersed in an inert, ethanol-soluble powder. To prepare a GC calibration curve, a weighed amount of the material is dissolved in a known volume of ethanol and appropriate aliquots are injected into the gas Chromatograph.Solutions of known concentrations of NG and EGDN were provided by Hercules, Inc. These solutions were quantitatively prepared from analyzed mixtures of the compounds and are used for plant quality control in the manufacture of explosive products and in industrial hygiene applications. Aliquots of these solutions, appropriately diluted, may be injected directly into the gas Chromatograph. Department of Transportation regulations may limit the shipment of such solutions by public transportation.A sample of analyzed dynamite containing EGDN but no NG was provided by Atlas Chemical Industries, ICI America, Inc. A weighed quantity of the dynamite is dispersed in ethanol, filtered, washed with ethanol, and diluted to a known volume. Aliquots of this solution are injected. Since dynamite is a heterogeneous material, care must be taken to obtain a representative sample.The pharmaceutical-grade sublingual NG tablets may be obtained from wholesale drug dealers. These tablets are manufactured to meet United States Pharmacopeia specifications, which require that the actual NG content be between 80 and 112% of the stated volume. The actual NG content of a specific lot of tablets may be obtained from the manufacturer. For use, the tablets are weighed, crushed, and extracted with ethanol, the solution is filtered and diluted to a fixed volume, and aliquots are injected.
Formulation development and evaluation of orodispersible tablet of Azelnidipine by factorial design and its comparison with the marketed formulation
Published in Particulate Science and Technology, 2023
Ramdas T. Dolas, Pooja D. Ware
The ODT was prepared by direct compression method according to the formula given in Table 2. The direct compression method is the easiest way to manufacture tablets. In recent times, this technique has been applied to produce fast dissolving tablets because of the availability of improved tablet excipients, especially tablet disintegrants. Nine batches were prepared by using Superdisintegrant croscarmellose Sodium. Azelnidipine, Avicel 102, Mannitol, Aspartame, Lactose, Magnesium stearate, and Talc were passed through mesh no. 60 separately and collected. Azelnidipine, mannitol, and lactose were mixed uniformly with gentle trituration using mortar and pestle to get a uniform mixture. The required quantity of Croscarmellose sodium, Avicel 102, and aspartame were taken as per formulation requirement and mixed with the above mixture. After the trituration mixer was placed in RMG (Rapid Mixer Granulator) for 30 min at 150 rpm. Finally, magnesium stearate and talc were added and mixing was continued for a further 5 min. The mixed blend of drug and excipients were compressed using a 9.7 mm punch on 10 stations “B” Tooling Rotary Tablet press to produce convex-faced tablets, weighing 250 mg each. Before tablet preparation, the mixture blend of all the ingredients was subjected to precompression parameters like Angle of repose, Bulk density, Tapped density, Compressibility index, and Hausner’s ratio.
Preparation, Characterization and ex vivo Intestinal Permeability Studies of Ibuprofen Solid Dispersion
Published in Journal of Dispersion Science and Technology, 2019
Thais Francine Ribeiro Alves, Cecília Torqueti Barros, Denicezar Baldo, Venâncio Alves Amaral, Mirella Sever, Carolina Santos, Patrícia Severino, Marco Vinicius Chaud
The clinical use of poorly water-soluble drugs has become a big challenge in pharmaceutical development due to the compromised bioavailability of the drugs in vivo.[24] Different strategies have been described to enhance the solubility and dissolution rate of the water-soluble poorly drugs such as salt formation, conventional trituration and grinding, ball milling, micellar and molecular complexation, fluid energy micronization and nanorecristalization. Although the reduction of particle size can be easily a directly accomplished, the resultant fine particles may not produce the expected result such as its solubility in organic media. Although it is possible the use of surfactants or co-solvents, these options can lead to adverse side effects and toxicity.[25] On the other hand, SD is more efficient due to an effect combination that can be achieved during the preparation process.[26] Generally, the SD with water-soluble carrier improved the wettability, modification of crystalline state, increase of surface area and produce faster dissolution and absorption.[19,27,28]
The chemical identity of “[Ag(py)2]MnO4” organic solvent soluble oxidizing agent and new synthetic routes for the preparation of [Ag(py)n]XO4 (X = Mn, Cl, and Re, n = 2–4) complexes
Published in Journal of Coordination Chemistry, 2018
István E. Sajó, Gréta B. Kovács, Tibor Pasinszki, Petra A. Bombicz, Zoltán May, Imre M. Szilágyi, Anna Jánosity, Kalyan K. Banerji, Rajni Kant, László Kótai
Using pyridine as the solvent, the crystallization of a 1:1 mixture of 2a:4a resulted in the transformation of 2a into 4a (1:10 mixed product was formed), while in pyridine-chloroform (1:5, v/v) a mixture of amorphous decomposition products was obtained only. Pure 2a or 4a crystallization in pyridine resulted in the formation of 5a, but due to the decomposition of 5a, 4a could be isolated as the final product. Recrystallization of pure 2a from acetone-benzene (1:1, v/v) resulted in a mixture of 3a and 4a (3a:4a = 4:1). Pure 4a behaved similarly, but produced only small amounts of 3a (3a:4a = 1:10). Trituration of solid 4a with this solvent mixture and with pure benzene resulted in increasing the 3a:4a ratio to 1:4 and 3:2, respectively. Gentle heating (40 °C) caused the most remarkable effect, the 3a:4a ratio was changed to 6:1. Results of recrystallization experiments performed with pure 2a, 4a, and their mixtures in various solvents are summarized in Table 2. The general interconversion scheme for compounds 1a–5a can be seen in Figure 1.