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Basic Methods
Published in Josef Hladovec, Antithrombotic Drugs in Thrombosis Models, 2020
To investigate the possible role of 5-HT vasoactivity in the model a nitrate preparation, pentaerythritol tetranitrate (PETN) was at a dose of 0.3 mg/kg administered orally 1 h before sham operation or clip insertion (Figure 35). Whereas 5-HT alone did not influence the sham-operated controls, PETN produced a significant temperature increase not affected by the addition of 5-HT. In animals with aortic clips, PETN showed an insignificant tendency to increases in temperature, probably by decreasing peripheral resistance. On the whole, the effect of 5-HT was preserved at a somewhat higher level after the addition of PETN.
Emollient Esters and Oils
Published in Randy Schueller, Perry Romanowski, Conditioning Agents for Hair and Skin, 2020
John Carson, Kevin F. Gallagher
Ethoxylation of ethylene glycol or diethylene glycol is used to produce high-molecular-weight dihydroxy or polyether polymers of approximately 6000 daltons (or 150 oxyethyiene repeat units). These materials are then esterified with stearic acid to produce viscosity-building agents. The well-known PEG-6000 distearate (PEG-150 distearate) is a material of this type. More recently, materials based on pentaerythritol ethoxylates have been made available. These are the tetrastearate esters of PEG-150 pentaerythritol. These materials have enhanced viscosity-building ability due to the three-dimensional structure conferred upon them by the central tetrahedral pentaerythritol molecule.
Wound healing and ulcers
Published in Ronald Marks, Richard Motley, Common Skin Diseases, 2019
Medical treatment is only helpful in the earliest and mildest cases. Keeping the affected part warm and protecting it from injury are important. Peripheral vasodilating drugs are only marginally useful (e.g. pentaerythritol tetranitrate, glyceryl trinitrate, isosorbide dinitrate, nifedipine). Drugs promoting vascular flow, such as hydroxyethyl rutosides and oxpentifylline, are rarely helpful.
In vitro metabolism of HMTD and blood stability and toxicity of peroxide explosives (TATP and HMTD) in canines and humans
Published in Xenobiotica, 2021
Michelle D. Gonsalves, Lindsay McLennan, Angela L. Slitt, James L. Smith, Jimmie C. Oxley
Energetic materials can be classified by chemical structure; including nitrate esters, nitroaromatics, nitroamines, peroxide, and others. The toxicity of most military explosives is well-characterised, with even some therapeutic properties being identified. For example, nitrate ester explosives, such as nitroglycerine and pentaerythritol tetranitrate (PETN), are widely used as vasodilators to treat angina (FDA 2014). Ill side effects have been linked to other explosives. Nitroaromatic explosives, such as TNT (2,4,6-trinitrotoluene), picric acid (2,4,6-trinitrophenol), and tetryl (2,4,6-trinitrophenyl-N-methylnitramine), may cause cytotoxicity, their metabolic pathways include single- or two-electron enzymatic reduction that forms radical species (Nemeikaite-Ceniene et al.2006). Nitroamine explosives, such as RDX (1,3,5-trinitro-1,3,5-triazinane) and HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazoctane), may be carcinogenic, their metabolic pathways promote the formation of N-nitroso species which cause genetic damage (Pan et al.2007). However, the metabolic pathways and toxicity of peroxide explosives, such as triacetone triperoxide (TATP) (Colizza et al.2019, Gonsalves et al.2020) and hexamethylene triperoxide diamine (HMTD, Figure 1) have not been thoroughly investigated.
Development of probiotic orodispersible tablets using mucoadhesive polymers for buccal mucoadhesion
Published in Drug Development and Industrial Pharmacy, 2020
Anja Hoffmann, Joerg T. Fischer, Rolf Daniels
Commonly used carbomer is composed of acrylic acid slightly crosslinked by allyl ether of pentaerythritol or sucrose [25]. The mode of mucoadhesion is described on the one hand as physical chain entanglement of polymer and mucin and on the other hand as hydrogen bonding [9,11,26]. The pH of the surrounding medium influences the mechanism of mucoadhesion. As Andrews et al. state, polymers with undissociated anionic pendant functional groups have great potential for hydrogen bonding between polymer and mucus, this would be the case for a pH below its pKa (6 ± 0.5) [27,28]. Contradictory, if pH exceeds pKa, more and more side chains of the polymer will lose their protons and acquire a negative charge and hydrogen bonds are less likely to form. The electrostatic repulsion of the carboxylate anions triggers chain extension and the polymer chains become available for interdiffusion and interpenetration [27].
A biocompatible reverse thermoresponsive polymer for ocular drug delivery
Published in Drug Delivery, 2019
Asitha Balachandra, Elsa C. Chan, Joseph P. Paul, Sze Ng, Vicki Chrysostomou, Steven Ngo, Roshan Mayadunne, Peter van Wijngaarden
Pentaerythritol (PE) (3.2131 g, 1 mole), DL-Lactic acid (42.5177 g, 18 moles) and ε-Caprolactone (16.1622 g, 6 moles) were heated in a round bottom flask 160–170 °C in the presence of tetrahydrofuran (THF), 250 mL and 1.0 g of p-toluenesulphonic acid monohydrate. The reaction mixture was allowed to stir for 3 days at reflux and ambient pressure. The water generated was collected using a Dean-Stark apparatus. The solvent was decanted and the reaction mixture concentrated using a rotary evaporator and the residual solvent removed under high vacuum to produce a slightly yellow transparent product (∼80% yield) (Theoretical MW – 2118.43, GPC MW as observed: Mn 2766, Mw 3469, Mp 3356, Mz 4266, PD 1.25).