Solid state analysis

Moller, K. and Gevert, T. 1994, An FTIR solid-state analysis of the diffusion of hindered phenols in low-density polyethylene (LDPE) the effect of molecular size on the diffusion coefficient. J. Appl. Polym. Sci. 51 895-903. 

R. Vehring, Red-excitation dispersive Raman spectroscopy is a snitable techniqne for solid-state analysis of respirable pharmaceutical powders, Appl. Spectrosc., 59, 286-292 (2005). 

K. Pollanen, A. Hakkinen, S-P. Reinikinen, J. Rantanen, M. Kaijalainen, M. Louhi-Kultanen and L. Nystrom, IR spectroscopy together with multivariate data analysis as a process analytical tool for in-hne monitoring of crystallization process and solid-state analysis of crystalline product, J. Pharm. Biomed. Anal., 38, 275-284 (2005). 

This section considers aspects and examples of the dissolution behaviour of individual iron oxides. Additional data are listed in Table 12.3 for a range of experimental conditions. As yet, characteristic dissolution rates carmot be assigned to the various iron oxides (Blesa Maroto, 1986). There are, however, some consistent differences between oxides with considerable stability differences, hence a comparison of the oxides is included here. In addition, the reactivity of any particular oxide may vary from sample to sample, depending on its source (natural or synthetic) and the conditions under which it formed. To illustrate this. Table 12.4 summarizes conditions and results from dissolution experiments in which a range of samples of the same oxide was compared. How the properties of the sample influence its dissolution behaviour is still not fully understood. A thorough characterization of the samples by solid state analysis, e. g. by EXAFS, to provide a basis for understanding the dissolution behaviour is, therefore, desirable. 

However, as methods such as XRD and ED, HRTEM, EXAFS, XPS and MS (see chapter 7), for long- and short-range solid-state analysis, were developed, more direct information especially about the nano-sized polymers was obtained (Atkinson et ak,... 

Scholz F, Meyer B (1994) Electrochemical solid state analysis - state of the art. Chem Soc Rev 23 341-347. 

Stephenson, G.A., Stowell, J.G., Toma, P.H., Dorman, D.E., Greene, J.R., and Byrn, S.R. (1994). Solid-state analysis of polymorphic, isomorphic, and solvated forms of dithromyfciAm. Chem. So,c116 1-9. 

For formulated products an essential analysis is the assay for API content. This is usually performed by HPLC, but Raman spectroscopy can offer a quantitative analytical alternative. These applications have been extensively researched and reviewed by Strachan et al. [48] and provide over 30 literature references of where Raman spectroscopy has been used to determine the chemical content and physical form of API in solid dosage formulations. As no sample preparation is required the determination of multiple API forms (e.g. polymorphs, hydrates/solvates and amorphous content) provides a solid state analysis that is not possible by HPLC. However, as previously discussed sampling strategies must be employed to ensure the Raman measurement is representative of the whole sample. A potential solution is to sample the whole of a solid dosage form and not multiple regions of it. As presented in Chap. 3 the emerging technique of transmission Raman provides a method to do just this. With acquisition times in the order of seconds, this approach offers an alternative to HPLC and NIR analyses and is also applicable to tablet and capsule analysis in a PAT environment. 

Solid state analysis of crystals obtained of receptor with acetate from water/methanol solutions reveal that once again the guanidiniocarbonylpyrrole cation exists in an extended conformation however in contrast to the proposed solution state model, the pyrrole NH points away from the guanidium NHs with the acetate anions bound by two separate receptor groups with solvent molecules helping to create a series of 2D arrays (figure 23c). 

Abott TP, Palmer DM, Gordon SH, Bagby MO (1988) Solid state analysis of plant polymers by FTIR J Wood Chem Technol 8 351-357... 

Brittain, H. G. Solid-State Analysis, Chapter 3. In Handbook of Modern Pharmaceutical Analysis (S. Ahuja and Scypinski, S., Eds.), pp. 57-84. Marcel Dekker, New York, 2001. 

Discovery of NCE and high-throughput screening Solid-state analysis of drug substances Degradation and impurity analysis of drug substances Preformulation analysis... 

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