Bioavailability animal

For the oral route of administration the dose was selected according to the experience from the FIM study, where this dose was safe and well tolerated and was in the dose-proportional range. The dose for the intravenous route of administration was adjusted according to the results from animal bioavailability studies where the absolute bioavailability was in the range of 50%. 

Bioavailability from Environmental Media. The bioavailability of ammonia from air and water has been examined rather extensively in animals. Bioavailability from soil has not been studied, although it is not a likely source of exposure. 

Engers, D., Teng, J., Jimenez-Novoa, J., Gent, P., Hossack, S., Campbell, C., Thomson, J. et al. A Solid-state approach to enable early development compounds Selection and animal bioavailability studies of an itraconazole amorphous solid dispersion. J. Pharm. Sci. 2010, 99(9), 3901-3922. 

Engers D, Teng J, Jimenez-Novoa J, Gent P, Hossack S, Campbell C, Thomson J, Ivanisevic 1, Templeton A, Bym S, Newman A (2010) A solid-state approach to enable eariy development compounds selection and animal bioavailability studies of an itraconazole amorphous solid dispersion. J Pharm Sd 99 3901-3922... 

Most foods of animal origin contain nicotinamide in the coenzyme form (high bioavialability). Liver and meat are particularly rich in highly bioavailable niacin. Most of the niacin in plants, however, occurs as nicotinic acid in overall lower concentrations and with a lower bioavailability. The major portion of niacin in cereals is found in the outer layer and its bioavailability is as low as 30% because it is bound to protein (niacytin). If the diet contains a surplus of L-tryptophan (Ttp), e.g., more than is necessary for protein synthesis, the liver can synthesize NAD from Trp. Niacin requirements are therefore declared as niacin equivalents (1 NE = 1 mg niacin = 60 mg Trp). 

Milk, milk products, and foods of animal origin contain high amounts of (free) riboflavin with good bioavailability. In foods of plant origin, the majority of riboflavin is protein-bound and therefore less bioavail-able. Cereal germs and bran are plant sources rich in riboflavin [1]. 

Plants contain to some extent less bioavailable forms of vitamin B6, e.g., glycosylates, or biologically inactive metabolites, e.g., e-pyridoxin-lysin-complexes. In addition, the release of vitamin B6 from foods rich in fiber is assumed to be delayed. The bioavailability of vitamin B6 from animal-derived foods is therefore overall higher than from plant-derived foods. Good dietary sources of vitamin B6 include chicken, fish, pork, beans, and pulses [1]. 

Compound 34 (BCZ-1812, RWJ-270201, peramivir) showed selective inhibition of influenza virus sialidases over bacterial and mammalian sialidases (Babu et al. 2000 Bantia et al. 2001 Sidwell and Smee 2002). Successful inhibition of influenza virus infectivity in vitro (Smee et al. 2001) and upon oral administration in vivo [mice (Bantia et al. 2001) and ferrets, reviewed in Sidwell and Smee 2002] led to human clinical trials of orally administered peramivir (Barroso et al. 2005). While orally administrated peramivir successfully completed animal studies and Phase I and Phase II clinical trials, in which the compound was showing neither major side effects nor toxicity (Sidwell and Smee 2002), preliminary results of the Phase III trials (June 2002) demonstrated no statistically significant difference in the primary efficacy endpoint, possibly due to low bioavailability (Barroso et al. 2005). 

Algae can be cultivated easily and quickly when compared to plants. They produce very high quantities of carotenoids compared to other sources (3.0 to 5.0% w/w on a dry weight basis). They contain both cis and trans isomers of carotenoids for high bioavailability and bioefflcacy, and also contain oxygenated carotenoids (xantho-phylls), which have greater bioactivity and better anticancer properties. The proteins from Dunaliella biomass can be utilized for bread and other products and whole cells can be utilized for animal, poultry, and fish foods because they are safe. ... 

Phytic acid (inisitol hexakisphosphate) is the main storage form of phosphorus in plants. The phosphorus is not bioavailable to non-ruminants as they lack the enzymes to break it down. Novozyme has developed a commercial enzyme, phytase, that can be added to animal feed to release the phosphorus. No inorganic phosphorus needs to be added. This shift in the source of phosphorous has a large impact on the environmental footprint of pig farming. 

The significance of P-gp, however, in affecting absorption and bioavailability of P-gp substrate drugs can be seen in studies in knockout mice that do not have intestinal P-gp. The gene responsible for producing that protein has been knocked out of the genetic repertoire. Those animals evidenced a sixfold increase in plasma concentrations (and AUC, area under the plasma concentration-time curve) of the anticancer drug paclitaxel (Taxol) compared to the control animals [54]. Another line of evidence is the recent report... 

A. D. Waston, Bioavailability and bioinequivalence of drug formulations in small animals, J. Vet. Pharmacol. Ther, 15, 151 (1992). 

The last step of the drug discovery process involves the testing of lead compounds to address issues such as efficacy, bioavailability, and safety. Testing may include in vitro assays but ultimately would require a suitable disease model and studies in animals. Many compounds may need to be designed and synthesized to identify the one compound with all the desired properties. Such a compound can be advanced to preclinical studies and eventually to the clinic. 

This type of information about a homologous series of drug candidates, when considered in light of the propensity of these compounds to undergo first-pass metabolism and/or liver clearance, allows pharmaceutical scientists to make more intelligent decisions about which compounds to move into animal studies. In addition, when an in vitro-in vivo correlation can be demonstrated for a series of compounds, the results of Caco-2 experiments can be used as a guide by medicinal chemists to make structural modifications to optimize oral bioavailability. 

Adult subjects who ingested soil (particle size less than 250 im) from the Bunker Hill NPL site absorbed 26% of the resulting 250 pg/70 kg body weight lead dose when the soil was ingested in the fasted state and 2.5% when the same soil lead dose was ingested with a meal (Maddaloni et al. 1998). There are no reported measurements of the absorption of soil-bome lead in infants or children. Additional evidence for a lower absorption of soil-bome lead compared to dissolved lead is provided from studies in laboratory animal models. In immature swine that received oral doses of soil from one of four NPL sites (75 or 225 ig Pb/kg body weight), bioavailability of soil-bome lead ranged from 50% to 82% of that of a similar... 

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