Kinetic temperature

Any time the yearly MKT of a facility approaches 25°C, the occurrence should be documented, the cause for such an occurrence should be investigated, and corrective actions should be taken to ensure that the facility is maintained within the established conditions for drug product storage. The FDA recognizes that, when the yearly MKT of a facility begins to exceed 25°C, it may not necessarily have an effect on products that have been stored for less than 1 year at the time, but it should be a warning that the facility itself may not be under adequate control. 

Handbook of Pharmaceutical Manufacturing Formulations Semisolid Products 

Stability data for a given strength may be bracketed by obtaining data for the smallest and the largest container and closure to be commercially marketed, provided that the intermediate container and closure is of comparable composition and design (Section VII.G). 

Extractables and Adsorption or Absorption of Drug Product Components 

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Table II summarizes the yields obtained from the CONGAS computer output variable study of the gas phase polymerization of propylene. The reactor is assumed to be a perfect backmix type. The base case for this comparison corresponds to the most active BASF TiC 3 operated at almost the same conditions used by Wisseroth, 80 C and 400 psig. Agitation speed is assumed to have no effect on yield provided there is sufficient mixing. The variable study is divided into two parts for discussion catalyst parameters and reactor conditions. The catalyst is characterized by kg , X, and d7. Percent solubles is not considered because there is presently so little kinetic data to describe this. The reactor conditions chosen for study are those that have some significant effect on the kinetics temperature, pressure, and gas composition.

The differences between palytoxin and PDBu with respect to kinetics, temperature dependence, and effect on low affinity binding suggest that these two different types of tumor promoters may be acting through different mechanisms. Further, in contrast to PDBu, the effect of palytoxin is not readily reversible (33). To determine where the two pathways differ, we compared the relative ability of palytoxin and PDBu to inhibit EGF binding in protein kinase C depleted cells. Swiss 3T3 cells were depleted of protein kinase C to different extents by exposing confluent quiescent cells to 0, 20, 200, or 2000 nM PDBu for 72 hr. Previous results indicate that this treatment depletes cells of protein kinase C activity in a dose-dependent manner (31). 

Chemical kinetics Temperature, concentration, and pressure None... 

Mean Kinetic Temperature — A single derived temperature that, if maintained over a defined period of time, affords the same thermal challenge to a drug substance or drug product as would be experienced over a range of both higher and lower temperatures for an equivalent defined period. The mean kinetic temperature is higher than the arithmetic mean temperature and takes into account the Arrhenius equation. 

When establishing the mean kinetic temperature for a defined period, the formula of J. D. Haynes (J. Pharm. Sci. 60 927-929, 1971) can be used. 

Fig. 2. Real kinetic temperature of the atmosphere, a measure of the kinetic energy of the molecules and atoms constituting the atmosphere is plotted against altitude above sea level here. Numerical values arc determined by the assumed molecular weight of the air (see Table 4). as well as assumed values of the...

The kinetic temperatures, TK,TR, and T T, are mainly given for completeness. The fact that these three temperatures are not equal indicates that our heuristic method for forcing each system to equilibrate at a preselected temperature was not 100% effective. The largest differences between these temperatures occur in the Stockmayer simulation of CO with p = 1.172 Debyes and in the Lennard-Jones etc., simulation of N2-... 

ORM assumes that the atmosphere is in local thermodynamic equilibrium this means that the temperature of the Boltzmann distribution is equal to the kinetic temperature and that the source function in Eq. (4) is equal to the Planck function at the local kinetic temperature. This LTE model is expected to be valid at the lower altitudes where kinetic collisions are frequent. In the stratosphere and mesosphere excitation mechanisms such as photochemical processes and solar pumping, combined with the lower collision relaxation rates make possible that many of the vibrational levels of atmospheric constituents responsible for infrared emissions have excitation temperatures which differ from the local kinetic temperature. It has been found [18] that many C02 bands are strongly affected by non-LTE. However, since the handling of Non-LTE would severely increase the retrieval computing time, it was decided to select only microwindows that are in thermodynamic equilibrium to avoid Non-LTE calculations in the forward model. 

In many cases, reactions in aqueous solutions are not at equilibrium. The failure to achieve equilibrium may be due to slow reaction kinetics, temperature fluctuations, biological activity, or open systems. For a reaction that is not at equilibrium, Equation 2.23 is not true ... 

Above the mesopause, Tg increases rapidly. In this region, termed the thermosphere (Fig. 2), absorption of short wavelength solar radiation is occurring (Fig. 3) which results in the efficient photodissociation of molecular oxygen, and the photoionization of the O atoms so produced and of the 02 and N2 molecules. Thus, Tg increases beyond 1000 K, approaching 2000 K at times. Whereas below 100 km the neutral gas particles, the ions and the electrons in the plasma all possess the same kinetic temperature, above 100 km, due to the lower pressure and the subsequent reduced electron/heavy particle collision frequency and the large amount of energy imparted to the photoelectrons, the electron temperature, Te increases above Tg (and Tj the ion temperature, which is Tg, see Fig. 2). 

As long as so little is known about the interstellar particle and photon radiation fields which provide the heating of the interstellar gas, one should not put too much faith in estimated equilibrium temperatures of dense gas clouds such as shown in Fig. 9. However, at least qualitatively it appears to be correct that dense condensations in the interstellar gas have low kinetic temperatures. In fact, gas-kinetic temperatures as low as 5 °K have been observa-tionally determined in the center of dark clouds. 

The determination of Tex and its interpretation in terms of the physical conditions which exist in interstellar clouds is an intriguing task of molecular radio astronomy. Two limiting cases are readily considered i) if the rate of collisionally induced transitions C(,i is small compared to the radiative rate then Tex is determined by the 2.7 °K radiation field and ii) if the reverse is true, then Tex % 7k, the kinetic temperature of the gas... 

In Section B we have discussed how the basic quantities of line emission and absorption, the excitation temperature Tex and optical depth r can be determined from observations. Energies required for rotational excitation are generally low enough (< 200 cm-1) so that the rotational levels are expected to be populated even at the very low kinetic temperatures of the interstellar molecular clouds. On the other hand, with a few exceptions such as H20 and NH3, one may assume that only the lowest energy levels of interstellar molecules are populated. Under these conditions the observable fractional column density Nx may not deviate appreciably from the total column density N of a molecule, which can be computed by means of Eq. (17) on the assumption of LTE. 

The population of the molecular energy levels in interstellar space is determined by microwave and infrared radiation and by collisions with various collision partners (including dust grains) having kinetic temperatures between 5 °K and < 100 °K. 

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