Solution stability area

The positiveness of the diffusion coeflicicnt (D > 0) in the solution stability area (including the mctastable region) is an important corollary of Equation 43 (cf. Equations 1.1.2-53,-55 with 43). In an absolutely unstable region... 

Range. Ideally, linearity should be established from 50% of the ICH reporting limit to the nominal concentration of drug substance in the sample solution (for area percent method). If the linearity does not support such a wide range of concentration, determine the linearity from 50% of the ICH reporting level to 150% of the proposed shelf life specifications of the related substance (for the high-low and external standard methods) as a minimum. This will ensure a linear response for related substances at all concentration levels to be detected during stability. 

The stability areas of the a-solid solutions depend both on the size of the rare earth ion and the temperature [147]. Increasing the size of the rare earth and decreasing temperature leads to a reduced solubility of A1 and O in the ass, e.g., to lower maximum n values [188], On the other hand, recent results show a more extended ass with more than one stabilising cation, as can expected with only one stabilising cation (different rare earths and Sr or Ca [128]). Even elements like La or Ce, which alone do not form an ass, can be effective as stabiliser together with Ca or Yb [131, 189]. Those multi-cation a-solid solutions offer additional possibilities of variations in processing and properties [154],... 

In experiments with rhodamine C mainly two types of curves (Figures 4 a, b, c, d) were constructed the first is characterized by fast colloid dissolution of dye and the solution stability (e.g., curves 2b, 3b) the other - by a longer stabilization period of solutions (curves 2a, 3 a), but with a sharp growth of solubilization effect for compositions in the area of the higher concentration (curve 9 a). For the compositions of the specified additives with cuccinimide the solubilization effect was more evident and the values of critical micelle concentration (CMC) were lower as compared with the features of individual substances in isooctane (Table 7). If sulfured piperylene fractions are characterized by the CMC interval of 0.05-0.45 mass.%, in the presence of 0.5 and 1.0 mass.% of cuccinimide the CMC areas correspond to the following values 0.02-0.50 and 0.01-0.50 mass.%. 

A reduction of the stability of the liquid crystalline phase means a reduced region where it is stable and a corresponding increase of the region for the inverse micellar solution. The present results agree with these predictions, and it is justifiable to relate the changes in stability areas mainly to modifications of the potential distribution within the electric double layers. 

Stability of solutions RSD (area) of a series of injections or standards... 

The second type of boundaries reflect the correlation between values pH and Eh at equilibrium between a compound of component B. in solution and water-insoluble mineral. On approach to the boundaries with mineral the dissolved compormd concentration closer to saturation. Thus, the second type of bounds determine conditions where component B. loses its migration capability. The position of this type of boundaries on the diagram is unstable. With the increasing concentration of component Bi in water, the mineral stability area increases, while the migration mobility area decreases. 

The third type of bounds separate stability areas of two water-insoluble minerals in the field of water Eh and pH values. Within the boimdaries of the stability fields of water-insoluble minerals migratory forms of the component B, are missing. At pH and Eh values of the stability fields of water-insoluble minerals component Bi is removed from the solution. 

Figure 14. Stability area of the a -SiAlON solid solution R jSii2-n-mAl . Ni6- 0 a) in the systems with R = Nd, Sm, Dy, Y and Yb at 1800-1900°C (after [14]) and b) in the area where elongated grain growth takes place in the a -SiAlON/p -SiAlON-plane (after [14,15,77,79]).

Fe(II) solutions in water are stable in absence of oxygen. But if oxygen is present and no acid has been added, one moves up in the diagram into the Fe(OH)3 region. The Fe ion is weakly acidic, so that the original solution may have pH about 5. The E value of, say, 0.1 M FeS04 is indeterminate. Equation (12-7) shows that some Fe(III) must form (by reaction with water), so that the E is not — 00, as a value of zero for (Fe ) produces in the Nernst equation. If one part per 10 forms Fe(III), the E is about 0.2 V, which lies in the Fe stability area at pH 5. 

Solution stability is important not only for solution or suspension products, but can also impact other properties such as solubility and dissolution data for other types of dosage forms. The effects of dissociation, recrystallization, ionization, complexation, and solution chemistry are all areas that will need further work to understand better how co-crystals will behave in various media. 

The stability area of Mn04 is markedly located above the frontier line corresponding to the oxidization of water into dioxygen under atmospheric pressure. From the same standpoint, 02(g) and Mn02(s) exhibit a common area. Despite all these considerations, pure aqueous solutions of the permanganate ion are surprisingly stable. Some of them have been stored for several years However, when manganous ions... 

A drop of a dilute solution (1%) of an amphiphile in a solvent is typically placed on tlie water surface. The solvent evaporates, leaving behind a monolayer of molecules, which can be described as a two-dimensional gas, due to tlie large separation between tlie molecules (figure C2.4.3). The movable barrier pushes tlie molecules at tlie surface closer together, while pressure and area per molecule are recorded. The pressure-area isotlienn yields infonnation about tlie stability of monolayers at tlie water surface, a possible reorientation of tlie molecules in tlie two-dimensional system, phase transitions and changes in tlie confonnation. Wliile being pushed togetlier, tlie layer at... 

Bronze disease necessitates immediate action to halt the process and remove the cause. For a long time, stabilization was sought by removal of the cuprous chloride by immersing the object in a solution of sodium sesquicarbonate. This process was, however, extremely time-consuming, frequentiy unsuccesshil, and often the cause of unpleasant discolorations of the patina. Objects affected by bronze disease are mostiy treated by immersion in, or surface appHcation of, 1 H-henzotriazole [95-14-7] C H N, a corrosion inhibitor for copper. A localized treatment is the excavation of cuprous chloride from the affected area until bare metal is obtained, followed by appHcation of moist, freshly precipitated silver oxide which serves to stabilize the chloride by formation of silver chloride. Subsequent storage in very dry conditions is generally recommended to prevent recurrence. 

Many stabilizer systems have been tailored to a particular industry need or for particular areas where dilution water quaUty is poor. These grades are heavily stabilized and may contain organic sequestering agents, ie, staimate, phosphates, and nitrate ions, so that the weak solutions produced by dilution from hard water retain acceptable stabihty. The nitrate is not a stabilizer, but it inhibits corrosion of aluminum storage tanks by chloride ion. 

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