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Tween 20
Polysorbate 20 (common commercial brand names include Kolliphor PS 20, Scattics, Alkest TW 20, Tween 20, and Kotilen-20) is a polysorbate-type nonionic surfactant formed by the ethoxylation of sorbitan monolaurate. Its stability and relative nontoxicity allows it to be used as a detergent and emulsifier in a number of domestic, scientific, and pharmacological applications. As the name implies the ethoxylation process leaves the molecule with 20 repeat units of polyethylene glycol; in practice these are distributed across 4 different chains, leading to a commercial product containing a range of chemical species. Food applications Polysorbate 20 is used as a wetting agent in flavored mouth drops such as Ice Drops, helping to provide a spreading feeling to other ingredients like Denatured alcohol, SD alcohol and mint flavor. The World Health Organization has suggested acceptable daily intake limits of 0–25 mg of polyoxyethylene sorbitan esters per kg body weight. Biotechnic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysorbate
Polysorbates are a class of emulsifiers used in some pharmaceuticals and food preparation. They are commonly used in oral and topical pharmaceutical dosage forms. They are also often used in cosmetics to solubilize essential oils into water-based products. Polysorbates are oily liquids derived from ethoxylated sorbitan (a derivative of sorbitol) esterified with fatty acids. Common brand names for polysorbates include Kolliphor, Scattics, Alkest, Canarcel, and Tween.Hubert Schiweck, Albert Bär, Roland Vogel, Eugen Schwarz, Markwart Kunz, Cécile Dusautois, Alexandre Clement, Caterine Lefranc, Bernd Lüssem, Matthias Moser, Siegfried Peters "Sugar Alcohols" Ullmann's Encyclopedia of Industrial Chemistry, 2012, Wiley-VCH, Weinheim. Examples * Polysorbate 20 (polyoxyethylene (20) sorbitan monolaurate) * Polysorbate 40 (polyoxyethylene (20) sorbitan monopalmitate) * Polysorbate 60 (polyoxyethylene (20) sorbitan monostearate) * Polysorbate 80 (polyoxyethylene (20) sorbitan monool ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purified Protein Derivative
Tuberculin, also known as purified protein derivative, is a combination of proteins that are used in the diagnosis of tuberculosis. This use is referred to as the tuberculin skin test and is recommended only for those at high risk. Reliable administration of the skin test requires large amounts of training, supervision, and practice. Injection is done into the skin. After 48 to 72 hours, if there is more than a five to ten millimeter area of swelling, the test is considered positive. Common side effects include redness, itchiness, and pain at the site of injection. Allergic reactions may occasionally occur. The test may be falsely positive in those who have been previously vaccinated with BCG or have been infected by other types of mycobacteria. The test may be falsely negative within ten weeks of infection, in those less than six months old, and in those who have been infected for many years. Use is safe in pregnancy. Tuberculin was discovered in 1890 by Robert Koch. Koch, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excipients
An excipient is a substance formulated alongside the active ingredient of a medication, included for the purpose of long-term stabilization, bulking up solid formulations that contain potent active ingredients in small amounts (thus often referred to as "bulking agents", "fillers", or "diluents"), or to confer a therapeutic enhancement on the active ingredient in the final dosage form, such as facilitating drug absorption, reducing viscosity, or enhancing solubility. Excipients can also be useful in the manufacturing process, to aid in the handling of the active substance concerns such as by facilitating powder flowability or non-stick properties, in addition to aiding ''in vitro'' stability such as prevention of denaturation or aggregation over the expected shelf life. The selection of appropriate excipients also depends upon the route of administration and the dosage form, as well as the active ingredient and other factors. A comprehensive classification system based on structure- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-ionic Surfactants
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysorbate 80
Polysorbate 80 is a nonionic surfactant and emulsifier often used in pharmaceuticals, foods, and cosmetics. This synthetic compound is a viscous, water-soluble yellow liquid. Chemistry Polysorbate 80 is derived from polyethoxylated sorbitan and oleic acid. The hydrophilic groups in this compound are polyethers also known as polyoxyethylene groups, which are polymers of ethylene oxide. In the nomenclature of polysorbates, the numeric designation following polysorbate refers to the lipophilic group, in this case, the oleic acid (see polysorbate for more detail). The full chemical names for polysorbate 80 are: *Polyoxyethylene (20) sorbitan monooleate *(x)-sorbitan mono-9-octadecenoate poly(oxy-1,2-ethanediyl) The critical micelle concentration of polysorbate 80 in pure water is reported as 0.012 mM. Other names E number: E433 Brand names: *Kolliphor PS 80 - Kolliphor is a registered trademark of BASF *Alkest TW 80 *Scattics *Canarcel *Poegasorb 80 *Montanox 80 – Montanox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe2+Fe3+2O4. It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism. Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5–6 and leaves a black streak. Small grains of magnetite are very common in igneous and metamorphic rocks. The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ''ferrous-ferric oxide''. Properties In addition to igneous rocks, magnetite also occurs in sedimentary rocks, including banded iron formations and in lake and marine sediments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastomer
An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of ''elastic polymer'', is often used interchangeably with rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation is feasible without breaking of covalent bonds. At ambient temperatures, such rubbers are thus relatively compliant ( E ≈ 3 M Pa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts. Application areas for different types of rubber are manifold and cover segments as diverse as tires, soles for shoes, and damping and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philatelists
Philately (; ) is the study of postage stamps and postal history. It also refers to the collection and appreciation of stamps and other philatelic products. Philately involves more than just stamp collecting or the study of postage; it is possible to be a philatelist without owning any stamps. For instance, the stamps being studied may be very rare or reside only in museums. Etymology The word "philately" is the English transliteration of the French "", coined by Georges Herpin in 1864. Herpin stated that stamps had been collected and studied for the previous six or seven years and a better name was required for the new hobby than ''timbromanie'' (roughly "stamp quest"), which was disliked.Williams, L.N. & M. ''Fundamentals of Philately''. State College: The American Philatelic Society, 1971, p.20. The alternative terms "timbromania", "timbrophily", and "timbrology" gradually fell out of use as ''philately'' gained acceptance during the 1860s. Herpin took the Greek root word Ï ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suspension (chemistry)
In chemistry, a suspension is a heterogeneous mixture of a fluid that contains solid particles sufficiently large for sedimentation. The particles may be visible to the naked eye, usually must be larger than one micrometer, and will eventually settle, although the mixture is only classified as a suspension when and while the particles have not settled out. Properties A suspension is a heterogeneous mixture in which the solute particles do not dissolve, but get suspended throughout the bulk of the solvent, left floating around freely in the medium. The internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation, with the use of certain excipients or suspending agents. An example of a suspension would be sand in water. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid, in which the colloid particles are smaller and do not settle. Colloids a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emulsion
An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms ''colloid'' and ''emulsion'' are sometimes used interchangeably, ''emulsion'' should be used when both phases, dispersed and continuous, are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, homogenized milk, liquid biomolecular condensates, and some cutting fluids for metal working. Two liquids can form different types of emulsions. As an example, oil and water can form, first, an oil-in-water emulsion, in which the oil is the dispersed phase, and water is the continuous phase. Second, they can form a water-in-oil emulsion, in which water is the dispersed phase and oil is the continuous phase. Multiple emulsions are also pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excipient
An excipient is a substance formulated alongside the active ingredient of a medication, included for the purpose of long-term stabilization, bulking up solid formulations that contain potent active ingredients in small amounts (thus often referred to as "bulking agents", "fillers", or "diluents"), or to confer a therapeutic enhancement on the active ingredient in the final dosage form, such as facilitating drug absorption, reducing viscosity, or enhancing solubility. Excipients can also be useful in the manufacturing process, to aid in the handling of the active substance concerns such as by facilitating powder flowability or non-stick properties, in addition to aiding ''in vitro'' stability such as prevention of denaturation or aggregation over the expected shelf life. The selection of appropriate excipients also depends upon the route of administration and the dosage form, as well as the active ingredient and other factors. A comprehensive classification system based on structure- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysis
Lysis ( ) is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" ) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a ''lysate''. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles. Many species of bacteria are subject to lysis by the enzyme lysozyme, found in animal saliva, egg white, and other secretions. Phage lytic enzymes (lysins) produced during bacteriophage infection are responsible for the ability of these viruses to lyse bacterial cells. Penicillin and related β-lactam antibiotics cause the death of bacteria through enzyme-mediated lysis that occurs after the drug causes the bacterium to form a defective cell wall. If the cell wall is completely lost and the penicillin was used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
