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Carr Index
The Carr index (Carr's index or Carr's Compressibility IndexPodczeck, Fridun & Brian E. Jones, eds. 2007. ''Pharmaceutical Capsules''111.) is an indicator of the compressibility of a powder. It is named after the scientist Ralph J. Carr, Jr. The Carr index is calculated by the formula C=100\frac, where \rho_B is the freely settled bulk density of the powder, and \rho_T is the tapped bulk density of the powder after "tapping down". It can also be expressed as C=100(1-\rho_B/\rho_T). The Carr index is frequently used in pharmaceutics as an indication of the compressibility of a powder. In a free-flowing powder, the bulk density and tapped density would be close in value, therefore, the Carr index would be small. On the other hand, in a poor-flowing powder where there are greater interparticle interactions, the difference between the bulk and tapped density observed would be greater, therefore, the Carr index would be larger. A Carr index greater than 25 is considered to be an ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camille Georges Wermuth
Camille Georges Wermuth (died September 2015) was a chemist in the Laboratoire de Pharmacochimie Moleculaire at the Universite Louis Pasteur in Illkirch, France. He is particularly known for his editing of ''The Practice of Medicinal Chemistry'' (1996) which has been issued in four editions. Selected publications *''The Practice of Medicinal Chemistry''. 1996. References 20th-century French chemists Year of birth missing 2015 deaths {{France-chemist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressibility
In thermodynamics and fluid mechanics, the compressibility (also known as the coefficient of compressibility or, if the temperature is held constant, the isothermal compressibility) is a measure of the instantaneous relative volume change of a fluid or solid as a response to a pressure (or mean stress) change. In its simple form, the compressibility \kappa (denoted in some fields) may be expressed as :\beta =-\frac\frac, where is volume and is pressure. The choice to define compressibility as the negative of the fraction makes compressibility positive in the (usual) case that an increase in pressure induces a reduction in volume. The reciprocal of compressibility at fixed temperature is called the isothermal bulk modulus. Definition The specification above is incomplete, because for any object or system the magnitude of the compressibility depends strongly on whether the process is isentropic or isothermal. Accordingly, isothermal compressibility is defined: :\beta_T=-\ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powder (substance)
A powder is a dry solid composed of many very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms ''powder'' and ''granular'' are sometimes used to distinguish separate classes of material. In particular, ''powders'' refer to those granular materials that have the finer grain sizes, and that therefore have a greater tendency to form clumps when flowing. ''Granulars'' refer to the coarser granular materials that do not tend to form clumps except when wet. Types Many manufactured goods come in powder form, such as flour, sugar, ground coffee, powdered milk, copy machine toner, gunpowder, cosmetic powders, and some pharmaceuticals. In nature, dust, fine sand and snow, volcanic ash, and the top layer of the lunar regolith are also examples. Because of their importance to industry, medicine and earth science, powders have been studied in great detail by chemical engineers, mechanical engineers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship between given quantities. The plural of ''formula'' can be either ''formulas'' (from the most common English plural noun form) or, under the influence of scientific Latin, ''formulae'' (from the original Latin). In mathematics In mathematics, a formula generally refers to an equation or inequality relating one mathematical expression to another, with the most important ones being mathematical theorems. For example, determining the volume of a sphere requires a significant amount of integral calculus or its geometrical analogue, the method of exhaustion. However, having done this once in terms of some parameter (the radius for example), mathematicians have produced a formula to describe the volume of a sphere in terms of its radius: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulk Density
In materials science, bulk density, also called apparent density, is a material property defined as the mass of the many particles of the material divided by the bulk volume. Bulk volume is defined as the total volume the particles occupy, including particle's own volume, inter-particle void volume, and the particles' internal pore volume. Bulk density is useful for materials such as powders, granules, and other "divided" solids, especially used in reference to mineral components (soil, gravel), chemical substances, pharmaceutical ingredients, foodstuff, or any other masses of corpuscular or particulate matter ( particles). Bulk density is not the same as the ''particle density'', which is an intrinsic property of the solid and does not include the volume for voids between particles (see: density of non-compact materials). Bulk density is an extrinsic property of a material; it can change depending on how the material is handled. For example, a powder poured into a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharmaceutics
Pharmaceutics is the discipline of pharmacy that deals with the process of turning a new chemical entity (NCE) or an existing drug into a medication to be used safely and effectively by patients. The patients could be either humans or animals. Pharmaceutics helps relate the formulation of drugs to their delivery and disposition in the body. Pharmaceutics deals with the formulation of a pure drug substance into a dosage form. Description Pharmaceutics is also called the science of dosage form design. There are many chemicals with pharmacological properties, but need special measures to help them achieve therapeutically relevant amounts at their sites of action. Branches Branches of pharmaceutics include: *Pharmaceutical formulation * Pharmaceutical manufacturing * Dispensing pharmacy * Pharmaceutical technology * Physical pharmacy * Pharmaceutical jurisprudence History Pharmaceutics deals with the formulation of a pure drug substance into a dosage form. Pure drug substanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hausner Ratio
The Hausner ratio is a number that is correlated to the flowability of a powder or granular material. It is named after the engineer Henry H. Hausner (1900–1995). The Hausner ratio is calculated by the formula ::H=\frac where \rho_B is the freely settled bulk density of the powder, and \rho_T is the tapped bulk density of the powder. The Hausner ratio is not an absolute property of a material; its value can vary depending on the methodology used to determine it. The Hausner ratio is used in a wide variety of industries as an indication of the flowability of a powder. A Hausner ratio greater than 1.25 - 1.4J. Cain (2002) "An alternative technique for determining ANSI/CEMA standard 550 flowability ratings for granular materials" ''Powder Hand. Proc'', Vol.14, No.3, pp 218-220. is considered to be an indication of poor flowability. The Hausner ratio (H) is related to the Carr index The Carr index (Carr's index or Carr's Compressibility IndexPodczeck, Fridun & Brian E. Jones, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Empirical
Empirical evidence is evidence obtained through sense experience or experimental procedure. It is of central importance to the sciences and plays a role in various other fields, like epistemology and law. There is no general agreement on how the terms ''evidence'' and ''empirical'' are to be defined. Often different fields work with quite different conceptions. In epistemology, evidence is what justifies beliefs or what determines whether holding a certain belief is rational. This is only possible if the evidence is possessed by the person, which has prompted various epistemologists to conceive evidence as private mental states like experiences or other beliefs. In philosophy of science, on the other hand, evidence is understood as that which '' confirms'' or ''disconfirms'' scientific hypotheses and arbitrates between competing theories. For this role, evidence must be public and uncontroversial, like observable physical objects or events and unlike private mental states, so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particulates
Particulate matter (PM) or particulates are microscopic particles of solid or liquid matter suspension (chemistry), suspended in the atmosphere of Earth, air. An ''aerosol'' is a mixture of particulates and air, as opposed to the particulate matter alone, though it is sometimes defined as a subset of aerosol terminology. Sources of particulate matter can be natural or anthropogenic hazard, anthropogenic. Particulates have impacts on climate and precipitation that adversely affect human health. Types of atmosphere, atmospheric particles include suspended particulate matter; thoracic and respirable particles; inhalable coarse particles, designated PM, which are granularity, coarse particles with a particle size, diameter of 10 micrometre, micrometers (μm) or less; fine particles, designated PM, with a diameter of 2.5 μm or less; ultrafine particles, with a diameter of 100 nm or less; and soot. Airborne particulate matter is a List of IARC Group 1 carcinogens, Group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
