XAS applied to pharmaceuticals:: drug administration and bioavailability

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 copperaminoacid 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.