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PEG 400
PEG 400 (polyethylene glycol 400) is a low-molecular-weight grade of polyethylene glycol. It is a clear, colorless, viscous liquid. Due in part to its low toxicity, PEG 400 is widely used in a variety of pharmaceutical formulations. Chemical properties PEG 400 is strongly hydrophilic. The partition coefficient In the physical sciences, a partition coefficient (''P'') or distribution coefficient (''D'') is the ratio of concentrations of a compound in a mixture of two immiscible solvents at equilibrium. This ratio is therefore a comparison of the solub ... of PEG 400 between hexane and water is 0.000015 (logP = -4.8), indicating that when PEG 400 is mixed with water and hexane, there are only 15 parts of PEG400 in the hexane layer per 1 million parts of PEG 400 in the water layer. PEG 400 is soluble in water, acetone, alcohols, benzene, glycerin, glycols, and aromatic hydrocarbons, and is slightly soluble in aliphatic hydrocarbons. References {{reflist *The Merck Index, 11 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyethylene Glycol
Polyethylene glycol (PEG; ) is a polyether compound derived from petroleum with many applications, from industrial manufacturing to medicine. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), depending on its molecular weight. The structure of PEG is commonly expressed as H−(O−CH2−CH2)n−OH. Uses Medical uses * Pharmaceutical-grade PEG is used as an excipient in many pharmaceutical products, in oral, topical, and parenteral dosage forms. * PEG is the basis of a number of laxatives (as ''MiraLax''). Whole bowel irrigation with polyethylene glycol and added electrolytes is used for bowel preparation before surgery or colonoscopy. * PEG is used in medicines for treating disimpaction and maintenance therapy for children with constipation. * When attached to various protein medications or drug carriers, polyethylene glycol of suitable length slows down their clearance from the blood. * The possibility that PEG could be used to fuse axons is being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are not attracted to water and may seem to be repelled by it. Hygroscopics ''are'' attracted to water, but are not dissolved by water. Molecules A hydrophilic molecule or portion of a molecule is one whose interactions with water and other polar substances are more thermodynamically favorable than their interactions with oil or other hydrophobic solvents. They are typically charge-polarized and capable of hydrogen bonding. This makes these molecules soluble not only in water but also in other polar solvents. Hydrophilic molecules (and portions of molecules) can be contrasted with hydrophobic molecules (and portions of molecules). In some cases, both hydrophilic and hydrophobic properties occur in a single molecule. An example of these amphiph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partition Coefficient
In the physical sciences, a partition coefficient (''P'') or distribution coefficient (''D'') is the ratio of concentrations of a compound in a mixture of two immiscible solvents at equilibrium. This ratio is therefore a comparison of the solubilities of the solute in these two liquids. The partition coefficient generally refers to the concentration ratio of un-ionized species of compound, whereas the distribution coefficient refers to the concentration ratio of all species of the compound (ionized plus un-ionized). In the chemical and pharmaceutical sciences, both phases usually are solvents. Most commonly, one of the solvents is water, while the second is hydrophobic, such as 1-octanol. Hence the partition coefficient measures how hydrophilic ("water-loving") or hydrophobic ("water-fearing") a chemical substance is. Partition coefficients are useful in estimating the distribution of drugs within the body. Hydrophobic drugs with high octanol-water partition coefficients are m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
