Good clinical practice and audits for dual X-ray absorptiometry and X-ray imaging laboratories and quality assurance centers involved in clinical drug trials, private practice, and research.

Good Clinical Practice (GCP) guidelines, with an emphasis on quality and validation of processes and data, must be applied to the use of imaging in clinical drug development. All participants, including the sponsor, principal investigator, site staff, quality assurance centers, and contract research organizations, must be cognizant of the need for application of these principles to their activities related to the imaging programs. This article discusses the various aspects of GCP as they need to be applied to the use of dual X-ray absorptiometry (DXA) for bone densitometry and X-rays for vertebral fracture assessment in clinical trials for osteoporosis, as well as research and private practice settings. The theory of proper audit conduct to verify clinical trial data is presented.

Preparative, analytical and fluorescence spectroscopic studies of sulphonated aluminium phthalocyanine photosensitizers.

Fluorescence spectroscopic studies were carried out on aluminium phthalocyanine with defined numbers (mono, di, tri and tetra) of sulphonate groups. Selective sulphonation was achieved using one of two synthetic methods to prepare a mixture of components which were separated using reverse-phase liquid chromatography. Fluorescence lifetimes were measured in methanol and buffer solution using time-correlated single-photon counting with picosecond laser excitation; the lifetime shows little variation with the number of sulphonate groups. Using steady state excitation, fluorescence quantum yields were determined for the tetrasulphonated component (phi F = 0.51) and, for comparison, unsulphonated aluminium phthalocyanine.