Chemically equivalent products, defined

Bioavailability, Bioequivalence, and Pharmacokinetics. Bioavailabihty can be defined as the amount and rate of absorption of a dmg into the body from an adrninistered dmg product. It is affected by the excipient ingredients in the product, the manufacturing technologies employed, and physical and chemical properties of the dmg itself, eg, particle size and polymorphic form. Two dmg products of the same type, eg, compressed tablets, that contain the same amount of the same dmg are pharmaceutical equivalents, but may have different degrees of bioavailabihty. These are chemical equivalents but are not necessarily bioequivalents. For two pharmaceutically equivalent dmg products to be bioequivalent, they must achieve the same plasma concentration in the same amount of time, ie, have equivalent bioavadabihties. 

Act = 226.5 the naming of the parents follows the nomenclature employed by Fajans in which the element uranium is referred to as UrI. A place in the periodic table is then defined by a specific row and a specific column. From the data, one then readily obtains the row and column of each of the elemental daughters. Since the characterization of decay products emphasized the fact that many of these products are chemically indistinguishable from one another, it is of course expected that many of the places in the last two rows of the periodic table are occupied by more than one elementary material. What is surprising is that these chemically equivalent materials have different atomic weights, some differing by as much as eight units. 

Furthermore, we have called a change involving the increase of by unity one equivalent of reaction. This is not entirely satisfactory since it is neither necessary nor always customary to write the stoichiometric equation for a reaction so that one chemical equivalent of each reactant and product is involved, but once the stoichiometric equation has been written down in order to define what is meant by the unit of reaction is also defined. The French phrase la reaction a marche une fois does not admit of direct translation. An alternative suggestion j has been made that when increases by unity the reaction should be said to have advanced by one de donder. 

In view of the electrochemical mechanisms of corrosion, the tendency for a metal to corrode can also be expressed in terms of the electromotive force (emf) of the corrosion cells that are an integral part of the corrosion process. Since electrical energy is expressed as the product of volts by coulombs Ovules, J), the relation between AG in joules and emf in volts, E, is defined by AG = -nFE, where n is the number of electrons (or chemical equivalents) taking part in the reaction, and F is the Faraday (96,500C/eq). The term AG can be converted from calories to joules by using the factor 1 cal = 4.184 absolute joules. 

The initial state of a reaction is defined by = 0, and the state at which = 1 corresponds to the final state where all the reactants (v, moles of R, and v2 moles of R2) have been converted to the products (v3 moles of P3 and v4 moles of P4) as shown in Fig. 1.4. We say one equivalent of reaction has occurred when a system undergoes a chemical reaction from the state of = 0 to the state of = 1. 

In modern terms, asphaltene is conceptually defined as the n-pentane-insoluble and benzene-soluble fraction whether it is derived from coal or from petroleum. There are a number of procedures used to isolate asphaltene (2-7), all of which appear to be reproducible (8) but do not necessarily provide equivalent end-products. The similarity between coal- and petroleum-derived asphaltenes begins and ends at the definition of the separation procedure. Puzinauskas and Corbett s (9) comments on asphalt may be paraphrased and applied to asphaltene. They state that the broad solvent classification is unfortunate it leads to misconceptions that petroleum and coal materials are alike, or at least similar. However, these two classes of materials differ not only in their origin, mode of manufacture and uses, but also in their chemical composition and physical behavior. 

Substances not included in the final inventory are defined as new and must be notified to the Federal Ministry of the Environment, Youth and the Family befcse they are manufactured or imported, unless notified mere than 10 years neviously. The authorities will publish an annual list of those substances which were notified 10 years earlier. New substances supplied exclusively for testing purposes are exempt from notification. Also exempt are those exported to specified countries where there are equivalent regulations for the notification or safety assessment of new substances, although the Austrian authorities must be notified in writing of the substance s identity and the expected production and expmt quantities, as well as the classification, labelling and proposed uses of hazardous substances. Finally, polymers are not notifiable, unless they contain >2% (by weight) in chemically-bound form of a new substance monomer. 

The first step is to define the ideal mentioned above. This will be taken as the choices of a social plaimer who is fully informed about aU aspects of the problem. This includes the benefits derived by society from the use of agricultural chemicals, the cost of their production, and the dynamics of environmental degradation, for both present and future generations. The critical piece of information for the analysis, however, is the social damage done by chemical use, or, equivalently, the social utility derived from an uncontaminated environment. The first best social plaimer (which will be denoted as FB) knows social damages from chemical use and incorporates them fully into her choices. 

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