Whole-body dose 462 Subject

The agent of choice for scabies is permerthrin 5% (Elimite) cream. Alternative agents in subjects who cannot use permethrin are crotamiton 10% (Eurax) and oral ivermectin (Stromectal) 200 mcg/kg as a single dose. To initiate the treatment with permerthrin, the skin should be scrubbed in a warm soapy bath to remove the scabs. The permerthrin lotion should then be applied to the whole body, avoiding the face, mucous membranes, and eyes, and left on for 8 to 14 hours. A single application eradicates 97% of scabies. All close contacts should be treated appropriately. The pruritus associated with scabies may persist for 2 to 4 weeks because of the remnants of mite parts in the skin. 

Radioactive Drugs If the drug is a radioactive drug, sufficient data from animal or human studies to allow a reasonable calculation of radiation-absorbed dose to the whole body and critical organs upon administration to a human subject are to be submitted. Phase 1 studies of radioactive drugs must include studies that will obtain sufficient data for dosimetry calculations. 

The majority of the 14C-human ADME studies are conducted with a small number of healthy adult subjects (often between 6-8) and if bile collection is needed, a small group of additional subjects are included [228], Traditionally, due to ethical reasons, male subjects are selected for the 14C-ADME studies. Before the start of the 14C-ADME studies, study sponsors have the responsibility to determine stability of the radiolabel, purity of the radiolabel (distinguishing degradants from metabolites is very important), and conduct tissue distribution studies in nonclinical species preferably using quantitative whole-body autoradiography (QWBA) to detect radioactivity in tissues, organs, and excreta to determine the safe radioactivity dose. Nonclinical tissue distribution study data are extrapolated and used to show that radioactivity exposure of a specific tissue/organ will be well below the allowable limits to humans [229,230], Most of the 14C-human ADME studies consider a total radioactivity dose of 100[tCi or less to be safe [231],... 

Tracer Adults (12) 17 (8-34) Healthy subjects without a pre-dosing fast. Absorption estimate based on whole body counting. LeRoy et al. 1966... 

Tracer in milk Adults (5) 11 Healthy subjects. Dose administered in milk, daily for 21-32 days. Absorption estimated from whole body retention kinetics. Rundo and Lilligraven 1966... 

The technique that uses doubly labeled water measmes the amoimt of COj produced by the whole body, and this is a good indicator of the rate of fuel oxidation. The subject consiunes a dose of water that contains isotopes of both hydrogen and oxygen. Specifically, the noiuadioactive isotopes used are deuterium ( H or D) and (as opposed to the usual O). After consiunption, the diffuses within the unlabeled water throughout... 

MALDI-MSI has previously been used in combination with whole-body antoradiolnminography (WBAL) to map the distribution of drngs and metabolites in dosed animals (8). The application of MALDI-MSI methods allows for the simnltaneous detection of mnltiple analytes of interest which can be identified by their molecnlar weight and specific fragmentation patterns. Subject to instrumental variance and parameter selection (snch as raster size and spectra acqnisition time and number) whole sections can be imaged rapidly (normally within several honrs for a standard 500 p,m raster) in comparison to WBAL which may require several days. 

It is relatively easy to assess the state of body reserves of vitamin C by measuring the excretion after a test dose. A subject whose reserves are saturated will excrete the whole of a test dose of500 mg of ascorbate over 6 hours. A more precise method involves repeating the loading test daily until complete excretion is achieved, thus giving an indication of how depleted the body stores were. 

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