Clearance, parameters

It is the advantage of the clearance parameter that only one clearance term is obtained. 

When describing the geometry of kneading discs, we omit the pitch value. We require instead the width of the discs and the distance between the disc centers (an additional clearance parameter). 

In a more thorough and balanced evaluation of the in vitro reactive metabolite tests in both human liver microsomes and S9 fractions, Obach et al. found that a panel of safe drugs in the clinic can form as much reactive metabolites as those hepatotoxic drugs, even after corrections for drug clearance parameters.92-93 Obviously, a more balanced and system-based approach to reactive metabolite formation and its clinical implications is needed hence forward. 

DeWoskin RS, Thompson CM (2008) Renal clearance parameters for PBPK model analysis... 

The renal clearance parameters of the peptides in the perfused rat kidney are presented in Table 5.1. Renal clearances of the peptides corrected for protein binding in the perfusate approached the glomerular filtration rate. Thus, the analysis of elimination mechanisms in perfused rat kidney confirmed that all agents under study were ehminated in the kidney, predominantly by glomerular filtration. 

AUometric scaling of PM parameters is the preferred approach during childhood. A major advantage of aUometric size adjustment is that it is a mechanistic approach that is based on dispersion theory (14, 15). This theory suggests that clearance parameters should be scaled by and volume parameters WT °. 

Reference to Eq. (3) shows that S is not a storage capacity in the ordinary sense. It has the dimension of volume and represents the volume of plasma which would contain the amount of BSP stored in the liver. In this light, the storage parameter S (milliliters of plasma) is analogous in a static sense to the classical clearance parameter C (ml/minute of plasma). 

Because Vmax - m can be obtained from in vitro metabolism experiments, development scientists may reasonably predict the in vivo clearance parameter of a low or intermediate extraction ratio drug from in vitro data, by use of Equations 17.13 and 17.17. By use of appropriate scaling factors, the in vivo clearance parameter in humans can be ap-... 

We next need to consider clearance parameters that are unaffected by hepatic blood flow and/or drug plasma protein binding. These parameters reflect the inherent ability of the hepatocytes to metabolize either total or unbound drug once it is presented to the liver. 

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