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The 234U/238U ratio in water, hair and nails samples was determined by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) and inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and by alpha-spectrometry for the water samples only. A correlation of 0.99 was found between the two ICPMS methods and of 0.98 with alpha-spectrometry. The range of activity ratios was between 0.9 and 2.6 according to the MC-ICPMS measurements. The reproducibility of both ICPMS techniques was better than 4% for water samples containing 1 µg l-1 of uranium and a 234U/238U atom ratio of 54.9 × 10-6. Sample preparation for the ICPMS consisted of dilution of water samples containing >10 µg l-1 of uranium and measurement time was ~1 mm, while alpha-spectrometry involved pre-concentration and separation of the uranium and counting times of 1000 mm. [ABSTRACT FROM AUTHOR]

The isotopic ratio 234U/238U in drinking water and in hair, toenail, and urine samples from 45 individuals who consumed 0.2-2775 μg d-1 of uranium in their drinking water was determined using a multi-collector inductively coupled plasma mass spectrometer (MC-ICPMS). The 234U/238U atom ratio in the water samples varied from 51 × 10-6 to 252 × 10-6 whereas in secular equilibrium (i.e., unity activity ratio) the ratio is 54.9 × 10-6. The correlation of the 234U/238U ratio between hair and nail samples was 0.98, and between hair and nails and urine the ratio was 0.91 and 0.89, respectively. The correlation of the ratio between water and the hair or nails was 0.97 but only 0.72 for water and urine, possibly due to spectral interferences. These results conclusively demonstrated that the uranium found in the bioassays can be traced to the drinking water, thus providing a direct link to the source of exposure. Hair may serve as an excellent indicator of occupational or environmental exposure to uranium and provide information regarding its source. Bioassay of hair is attractive as it is an effective bio-concentrator, samples can be easily stored, the concentration reflects an integrated value, and, finally, the measurement of the 234U/238U isotopic ratio in digested hair samples by MC-ICPMS is feasible and highly informative. Hair bioassay can also be used to assess exposure to depleted uranium long after the subjects have left the area suspected of contamination. [ABSTRACT FROM AUTHOR]

The future of dosage form design is expected to move towards the production of personalized dosage forms tailored to each patient. The 3D printer was introduced to solve that problem but is not easy to use in a pharmacy. Herein, a new 3D mold technology is adopted for tablet manufacturing. Preparation of amlodipine tablets was used as a Biopharmaceutics Classification System Class 1 drug model to study this technology. Different concentrations of either starch or Avicel-based formulations and different concentrations of hydroxypropyl methylcellulose as a binder for mass formation were used. The mass formed for each formula was cast into the mold for tablet preparation. Different non-pharmacopeial and pharmacopeial quality-control tests of the prepared tablets by using the 3D mold were compared to a marketed tablet product of amlodipine. 3D-molded tablets showed compliance properties with the tablet pharmacopeial quality standard. Studying the equivalence of the 3D mold tablets to the brand marketed product under biowaiver conditions was carried out. The difference and similarity factors studies of molded tablets prepared using starch or Avicel as a filler and 2.5% of hydroxypropyl methylcellulose showed acceptable characters to the drug brand name. It is predicted that by using this simple technique, it would be possible to produce tablets with designed disintegration and release profiles, which could potentially allow the tailoring of the drug release and hence personalize the medicine for each patient., (Copyright© by International Journal of Pharmaceutical Compounding, Inc.)

The (234)U/(238)U ratio in water, hair and nails samples was determined by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) and inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and by alpha-spectrometry for the water samples only. A correlation of 0.99 was found between the two ICPMS methods and of 0.98 with alpha-spectrometry. The range of activity ratios was between 0.9 and 2.6 according to the MC-ICPMS measurements. The reproducibility of both ICPMS techniques was better than 4% for water samples containing 1 mug l(-1) of uranium and a (234)U/(238)U atom ratio of 54.9 x 10(-6). Sample preparation for the ICPMS consisted of dilution of water samples containing >10 microg l(-1) of uranium and measurement time was approximately 1 min, while alpha-spectrometry involved pre-concentration and separation of the uranium and counting times of 1,000 min.