Stability Aspects

5 h (119,126) however, it can be increased by a factor of 20 or more in patients with renal insufficiency (127). Gadolinium has been indeed detected in skin and blood vessels of patients with NSF (128). 

The thermodynamic stability of an ML complex is expressed by the equilibrium constant of the formation reaction, Xml, or known as the stability constant  

This equilibrium is characterized by the protonation constant of the complex  

The protonation constants of the ligand, K, are also necessary for the calculation of the complex stability constant, XML  

Complex stability constants are often determined by pH-potentiometric titration of the ligand in the presence and absence of the metal ion (129). This method works well when equilibrium is reached rapidly (within few minutes), which is usually the case for linear ligands. For macrocyclic compounds, such as DOTA and its derivatives, complex formation is slow, especially at pH-s where the formation is not yet complete, therefore a batch method is used instead of direct titration (130,131). A few representative examples of stability constant data mainly collected from Ref. (132), on MRI relevant Gdm complexes are presented in Table IV. 

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In vivo reproducible results can only be achieved if the liposome-drug or -antigen combinations are thoroughly characterized upon preparation in terms of their physical and chemical properties and, besides, if the stability during storage is ensured. In this chapter both the pharmaceutical (preparation, characterization, and stability) aspects and the therapeutic potentials and limitations of drug and antigen delivery with liposomes will be discussed. 

Bernard, A.M. 1995. Biokinetics and stability aspects of biomarkers Recommendations for application in population studies. Toxicology 101(l-2) 65-71. 

One rarely used but powerful means of maximizing both content uniformity (as mentioned above) and stability aspects of low-dose pharmaceuticals is the formation of inclusion complexes to increase both the drug load in the formulation as well as the stability of the API. One specific example is the complexation of ethinyl estradiol in the form of its /3-cyclodextrin clathrate for use in pharmaceutical formulations.23 This inclusion complex has been successfully applied in the development of an ultralow-dose formulation of this steroid.24... 

Stability Aspects of Radiopharmaceuticals 1.3.6 Extemporaneous Preparation of Radiopharmaceuticals... 

With better understanding of the mechanism of degradation and stabilization, there undoubtedly will be an increased effort to produce polymers with greater photothermal/radiation resistance and also more effective stabilizers to achieve this end. Thus, the study of degradation and stabilization aspects of ethylene-propylene copolymers and their blends (and generally of multiphase polymer blends) appears to be both intellectually stimulating and of practical importance. 

In Table II we report the same illustrative example following the Gordon procedure. The convenience of the memory function method is apparent. Furthermore, the Gordon method fails unless 0, a restriction which is overcome in the memory function method. Another quite interesting P-algorithm has been provided by H ggi et al., and we refer to the original papers for illustration and discussion of stability aspects. 

Stability aspects of the cross-flow reactor-heat exchanger were the aim of a comprehensive study by Dcgnan and Wei [35,71], where the theoretical results were also verified experimentally. Of particular interest was the experimental demonstration of the multiplicity of the steady states for the autothermal countercurrent process case. 

Monkhouse, D. C. 1984. Stability aspects of preformulation and formulation of solid pharmaceuticals. Drug Dev. Ind. Pharm. 10 1373-1412. 

That the position of an element in the Periodic Table influences its chemistry is inevitable, and a consequence of the Periodic Table reflecting the electronic configuration of the element. However, it is less clearly recognized that elements within the same column (and hence with the same valence shell electron set) differ in their chemistry. It is instructive to overview the chemical impact of the central atom to illustrate both similarities and differences. These, along with specific examples of synthetic coordination chemistry, appear in Chapter 6, whereas shape and stability aspects are detailed in the next two chapters. 

Stability aspects of packaging, Drug Development and Industrial Pharmacy, Vol. 10, Nos 8 and 9, 1984. 

These few examples underline the importance of the stability aspect of salt selection. 

Van Dijkhuizen-Radersma R, Nicolas HM, Van de Weert M, Blom M, De Groot K, Bezemer JM. Stability aspects of salmon calcitonin entrapped in poly(ether-ester) sustained release systems. Int J Pharm 2002 248 229-237. 

Bischoff [102] showed that the generalized modulus concept of Eq. 3.6.b-8 can be extended by substituting the right hand side of Eq. 3.7.a-14 or Eq. 3.7.a-14a as the rate form. This then asymptotically unified all the isothermal and endothermic curves, and the suitable portions of the exothermic curves, but still would not permit prediction of the maxima or stability aspects. 

Compared with the carrier, the immobilization is better at hydrophilicity, chemical stability and thermal stability aspects. This polymer can be used in wastewater treatment which can remove metal ions and organic pollutants at the same time and can be reused through deabsorption. 

Chemical derivatization and stability aspects of selected avermectin derivatives known for their action against a broad range of nematode and anthropod animal parasites 12CPB931. 

The inactivated fermentation broth is stabilized further either by drying or through the addition of chemicals. The key stability aspects are the enzymatic activity and microbial stability. Antimicrobials and polyols are commonly added to the inactivated fermentation broth for stabilization, but the choice of chemicals is very restricted by... 

The fundamentals regarding ASD have already been introduced in the previous chapters and elsewhere (Taylor and Shamblin) readers are encouraged to use those for reference. This chapter introduces the mechanisms of instability and influencing factors, options to prevent instability, and methods to characterize API and other ingredients as well as to predict the instability. In addition, we introduce the typical stability programs applicable for early ASD development. It is important to note that this chapter mainly focuses on the physical stability aspects. Though not the focus of this chapter, chemical instability of ASD is of equal importance to physical instability (Pikal and Dellerman 1989). Chromatographic approach is the most widely adopted method for the assessment of chemical stability of both API and the key excipients. 

Additional discussion on the various aspects of geotechnical or soil deformations and stability aspects of foundation design is presented in the following sections for both the WSD and the LRFD methodologies. FHWA (2002) provides guidelines for the determination of soil and rock properties for use in the analysis and design of bridge foundations. 

In LRFD design, both the strength and extreme event limit states pertain to the strength or stability aspects of shallow foundation. The stability and stability mechanisms considered are the same as those mentioned earlier for the WSD stability analyses. 

Within the scope of the research on the stability of open slope revetments, much knowledge has been developed about the stability of rock under wave and current load and stability of placed (pitched) stone revetments under wave load. Until recently, no or unsatisfactory design tools were available for a number of other (open) types of revetment and for other stability aspects. This is why the design methodology for placed block revetments has recently been extended in applicability by means of a number of desk-studies for other (open) revetments ... 

Note that the function has been used throughout. It is of interest to mention that the set (9.246) constitute the relations used by Ergen, Weinberg, and Welton in their studies of the kinetics of circulating-fuel reactors. These studies place emphasis on the stability aspects of the nonlinear set (9.246) and include the extension of the present theory to account for the effects of alternate fuel paths through the core with different transit times as well as the effects of delayed neutrons. 

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