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Oxaliplatin is a second-generation platinum-based anticancer drug. Its degradation is studied in solution, in the presence of chloride ions (in neutral or acidic media) in excess. In both cases the degradation product precipitates immediately. The EXAFS spectra of these products show that they are identical. EXAFS modeling and refinement of the first coordination sphere shows that two light atoms are replaced by two chloride ions. The complete refinement of the local structure is possible by studying the multiple-scattering signal. The results show that the main multiple-scattering contribution is due to the binding oxalato group and that the degradation product is [Cl(2)-(diaminocyclohexane)-Pt(II)].

X-ray absorption spectroscopy provides valuable information on metallic speciation and so has a wide range of applications in bioinorganic systems. In this paper, low-molar-mass metallic complexes as used in pharmaceutical science are focused on. The results of structural studies on metal-based drugs applied as disease treatments, nutritional supplements or tools for diagnostic methods are presented. Then metal speciation (spatial and chemical distribution) in biological samples through micro-XANES imaging experiments are dealt with. Problems arising from the analysis of noisy data collected from these diluted samples are discussed.

The stability of carboplatin and oxaliplatin aqueous solutions has been studied under different chloride ions concentration and pH conditions. For both compounds, we demonstrate the chloration of the platinum first coordination shell.

We present selected XAS applications, focused towards practical hospital questions of drug administration and bioavailability, where the technique is driven up to its limits of sensitivity. i) XAS was used to study the interactions between the components of parenteral nutrition solutions, in particular zinc and aminoacids, possibly modifying their bioavailability. ii) We studied by EXAFS a series of binary and ternary copper-aminoacid complexes, in view of the development of an efficient oral drug against copper deficiencies in Menkes disease. iii) EXAFS and XANES analysis allowed us to characterise the solution form of a new arsenic containing drug against leukaemia. In parallel to the XAS measurements, we analysed trace elements levels along patients' hairs, using X-ray fluorescence excited by synchrotron radiation. The measurements along the hair allow for a monitoring of essential trace elements during therapy.