Factors Affecting Initiation Rates

The bioavailability of drugs from tablets can be markedly influenced by the rate and efficiency of the initial disintegration and dissolution process. Unfortunately, one is faced with a compromise situation — a structure that has both a durable structure prior to administration and the ability to readily break down when placed in the in vivo environment. One of the major factors affecting both these properties is the structure of the tablet, in particular its density (or porosity) and the pore structure. Study of the significance of such measurements and interpretation of the results is a relatively recent field of interest. 

It was found that three factors affect the biotransformation rates of A9PEO the origin of the bacterial culture, temperature, and the initial concentration of A9PE0n. Biotransformation kinetics of mixed bacterial cultures from the brackish water layer was faster than those from the saline water layer. Rate constants (based on first order kinetics) for... 

Moad G, Rizzardo E (1995) Alkoxyamine-initiated living radical polymerization factors affecting alkoxyamine homolysis rates. Macromolecules 28 8772-8728... 

In 1996, Delphi estimated the cost of processing wastes at 2.50 to 10.00/kg. Among the factors listed as affecting cost were quantity of waste, labor rates, initial contaminant concentration, characteristics of residual waste, waste handling and pretreatment, amount of debris, utility/fuel rates, and target contaminant concentration (D13821G, p. 24). 

The incremental reactivity of a VOC is the product of two fundamental factors, its kinetic reactivity and its mechanistic reactivity. The former reflects its rate of reaction, particularly with the OH radical, which, as we have seen, with some important exceptions (ozonolysis and photolysis of certain VOCs) initiates most atmospheric oxidations. Table 16.8, for example, also shows the rate constants for reaction of CO and the individual VOC with OH at 298 K. For many compounds, e.g., propene vs ethane, the faster the initial attack of OH on the VOC, the greater the IR. However, the second factor, reflecting the oxidation mechanism, can be determining in some cases as, for example, discussed earlier for benzaldehyde. For a detailed discussion of the factors affecting kinetic and mechanistic reactivities, based on environmental chamber measurements combined with modeling, see Carter et al. (1995) and Carter (1995). 

A similar phenomenon can be observed in the cuffs and balloons of tracheal tubes, flotation catheters, etc. Increases in cuff pressure may be sufficient to cause mucosal ischaemia with subsequent damage to the tracheal mucosa. In the case of pulmonary flotation catheters, there is a risk of cuff rupture followed by gas embolism and infarction. A number of factors affect the rate of volume and pressure change—time, permeability, elasticity, initial volume and pressure, nitrous oxide concentration, temperature. 

The amount of soil treated is not the only factor affecting cost, however. The following are the most commonly identified factors affecting the cost of treatment moisture content of the soil, soil characteristics, amount of debris with the waste, initial contaminant concentration, target contaminant concentration, and utility rates.f ... 

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