Authors:Faheem Rizvi, Tanveer Bokhari, S. Roohi, and A. Mushtaq
Doxorubicin (DOX) is an anthracycline antineoplastic and one of the most potent and widely used drugs in clinical oncology.
It is used in the treatment of a wide variety of cancers. The aim of this study was the direct labeling of DOX with 99mTc; its optimization, characterization and quality control of the radiolabeled DOX. Labeling efficiency was determined by
paper chromatography. More than 92% labeling was obtained at pH 6–7, 10–12 μg stannous chloride and 200 μg of DOX. The stability
of 99mTc–DOX was studied up to 5 h. All the experiments were performed at room temperature (25± 2 °C). The characterization of the
labeling compound was performed by HPLC and electrophoresis. Electrophoresis indicates that labeled DOX has no charge and
HPLC shows single specie of labeled compound.
Analytical quality control is needed to ascertain the reliability of results from all types of analysis, including activation analysis. Thea priori precision has to be combined with the statistics of counting in order to reach a state of statistical control. The Analysis of Precision is used to verify the absence of unknown sources of variability and to ascertain the absence of systematic biases or calibration errors by analyzing samples or reference materials with accurately known content or actual samples by an independent method.
Bioassay group of Indira Gandhi Centre for Atomic Research at Kalpakkam carries out routine surveillance of all radiation workers at the Centre by both whole-body counting and excreta analysis for assessing internal contamination. Various quality control measures adopted and experience gained in participating in inter-laboratory comparisons is highlighted.
Quality control, as applied in normal activation analysis by the simultaneous analysis of well-characterized quality control
samples, blanks and sometimes duplicates, cannot fully be applied in large sample analysis. Well characterized control samples
are, e.g., not available at the size of large samples. Different approaches have to be developed to monitor and to control
sources of errors in this new type of chemical analysis. Some of the measured sample parameters dealing with gamma-ray and
neutron attenuation can only vary between well known values of elemental constants. These parameters can much easier be determined
in large sample analysis than with samples in the milligram range, thus offering an outlook for direct verification of the
quality of the related correction algorithms. Some examples are given here from experience with the kg-scale neutron activation
analysis at the facilities in Delft.
A kit-like procedure is described for the labelling of Hippuran by exchange in a melt with carrier-free iodide-123 directly
formed from the decay of123Xe. Decay and subsequent melting for 15 min at 180°C are performed in one and the same ampoule. This results in a transfer
of 95% of the123I-activity into Hippuran with a residual123I-content of <1.0%. Quality control is based on thin-layer chromatography. Contaminants are discussed and a comparison is
made with commercial preparations of Hippuran-131I.
Thin-layer chromatography (TLC) is generally regarded as a common analytical technique. Everybody ‘knows’ it and it is used to some extent in almost every laboratory in the world. Unfortunately for most analysts TLC remains what it has been for many years — a rapid, simple, inexpensive, and not very precise tool. When one considers the latest technical and methodological developments, however, modern high-performance thin-layer chromatography (HPTLC), also known as planar chromatography, is a reliable and powerful analytical technique, which can be in full compliance with current good-manufacturing practice (cGMP). TLC is the method of choice when many samples must be compared, when flexibility is important, and when rapid quantitative and semi-quantitative data are needed at low cost per sample.
Quantitative calibration and quality control have been a major bottleneck in microanalysis due to the lack of natural-matrix
CRMs certified at sample sizes compatible with those of unknown samples. In this paper, a solution is described to characterize
sampling behavior for individual elements, so as to identify elements homogeneous enough at stated sample size levels in given
CRMs/RMs. By using a combination of several nuclear analytical techniques, INAA-EDXRF-µPIXE, sampling behavior for individual
elements can be characterized at sample size levels from grams down to pg. Natural-matrix CRMs specifically for QC of microanalysis
may thus be created. Additional information in certificates of these new generation CRMs is imagined.
Physico-chemical characterization of99mTc-radiopharmaceuticals is presented. Limiting pH values, iso-osmotic pressure and the apparent coefficient values between two immiscible phases are determined too. A selection of radiochromatographic methods /stationary or mobile phase/ for routine quality control of99mTc radiopharmaceuticals for radiochemical purity was made. The methods chosen are simple, accurate, sufficiently sensitive and fast in operation. The mean values were determined for99mTc radiopharmaceutical distribution per organs, characteristic for the tested preparates and for radiochemical purity, as well as the time interval from injection to sacrifice of the animals.
Authors:Rui Macêdo, Antonio Gouveia de Souza, Ana Miriam, and Carvalho Macêdo
A study was made of the thermal behavior of the starting materials, their mixtures and the resulting mebendazole tablets.
The thermal curves were obtained with a Shimadzu thermobalance, model TGA-50, using an air flow of 50 mL min−1 and a heating rate of 10°C min−1 in the temperature interval 30–900°C. The reaction constant velocities for the mebendazole salt and tablets were determined
isothermally, using the Arrhenius expression. The thermal stability of mebendazole tablets is lower than that of the mebendazole
salt, due to the presence of starch and lactose in the composition. Analysis of the data reveals that thermogravimetry is
a powerful tool in pharmaceutical technology and quality control.
Authors:V. Borghi, L. Lin, S. Silva, E. Haber, and B. Wajchenberg
This work reports the radioiodination of human thyrotropin (hTSH) in our laboratory (IPEN) and evaluates its quality in comparison with a commercial product. The radioiodination yield obtained in 20 experiments ranged from 18.5 to 56.3%, while the purification recovery ranged from 75.5 to 124.0% and the specific activity ranged from 1.01 to 3.10 MBq g–1. The values for the distribution coefficient revealed in the purification of radioiodinated hTSH ranged from 0.232 to 0.371. When tested concomitantly in the same radioimmunoassay system, the IPEN and the commercial tracer presented parallel standard curves. A highly significant correlation ion was observed between the quality control samples estimated through both curves (p<0.001). These results confirm the quality of the hTSH radioiodinated at IPEN and suggest the acquirement of self-sufficiency in this in vitro nuclear technology.