Blood plasma profiles

Fig. 6.6 Blood plasma profiles of octreotide after peroral administration of 15 mg/pig A, Subject 2 B, Subject 6. Core ( ) core inside ( ) octreotide without any polymer (A) core outside with TMC (x) (Dorkoosh et al. 2002)...

In order to obtain an in vitro-in vivo relationship two sets of data are needed. The first set is the in vivo data, usually entire blood/plasma concentration profiles or a pharmacokinetic metric derived from plasma concentration profile (e.g., cmax, tmax, AUC, % absorbed). The second data set is the in vitro data (e.g., drug release using an appropriate dissolution test). A mathematical model describing the relationship between these data sets is then developed. Fairly obvious, the in vivo data are fixed. However, the in vitro drug-release profile is often adjusted by changing the dissolution testing conditions to determine which match the computed in vivo-release profiles the best, i.e., results in the highest correlation coefficient. 

Concentration-time profile of the substance/metabolites in blood (plasma), tissues, and other biological fluids, such as urine, bUe, exhaled air, and the volume of the excreted fluids if appropriate... 

Resonance Raman Spectroscopy. A review of the interpretation of resonance Raman spectra of biological molecules includes a consideration of carotenoids and retinal derivatives. Another review of resonance Raman studies of visual pigments deals extensively with retinals. Excitation profiles of the coherent anti-Stokes resonance Raman spectrum of j8-carotene have been presented. Resonance Raman spectroscopic methods have been used for the detection of very low concentrations of carotenoids in blood plasma and for the determination of carotenoid concentrations in marine phytoplankton, either in situ or in acetone extracts. ... 

Preliminary in vivo experiments carried out on this biphasic pulsed release device containing ibuprofen as a model drug reveal two distinct peaks in plasma profiles, thus indicating that the in vitro results are in good agreement with the in vivo blood levels. 

As stated above, the Vss calculation using Eqs. (5) or (10) is valid only when elimination exclusively occurs from the sampling (plasma/blood) compartment. When some or all elimination occurs from the tissue compartment (Fig. 7.1), the concentration versus time profile will still be characterized by a bi-exponential equation however, the ability of modeling systems to quantify the micro rate constants is lost. That is to say, essentially identical bi-exponential concentration time profiles are possible with and without elimination from the tissue compartment. Therefore, when modeling from a plasma profile only, there is no way of determining if the exit of drug from the body is exclusive to the central compartment. 

Most drugs require access to tissues to exert their therapeutic effects. Therefore, when investigating the time course of a drug s action, understanding the rate and extent of transfer from blood plasma to the target tissues is essential. The pharmacokinetic profile can provide quantitative clues indicating that the drug is extensively distributed outside the plasma. 

Loor, J.J., Herbein, J.H. 2001. Alterations in blood plasma and milk fatty acid profiles of lactating Holstein cows in response to ruminal infusion of a conjugated linoleic acid mixture. Anim. Res. 50, 463 476. 

Immunoglobulin profiles of human cervical mucus indicate approximately twice as much IgG (30mg/dl) as IgA (15mg/dl) overall however, there are both biphasic and menstrual cycle influences on Ig levels [169], Different from blood plasma, the IgA2 subclass predominates in female genital tract secretions with lesser amounts of IgGAl [170],... 

FIGURE 2 (a) Schematic picture of blood plasma concentration profile after administra-... 

Exercise has been shown to reduce (28), and in some studies normalize (29,30) plasma triglyceride concentrations in persons with hypertriglyceridemia. In persons with hypercholesterolemia, plasma triglycerides and HDL cholesterol correlated with physical activity the most physically active men had the lowest plasma triglyceride and highest HDL cholesterol concentrations (31). Survivors of a myocardial Infarct also have favorable changes In their blood lipid profile In response to exercise of moderate intensity (32-36). 

The CarbE profile in humans is not well known. While CarbEs were considered to be absent from the blood plasma of humans (Li et al, 2005), they are, indeed, present in human erythrocytes and monocytes as well as in human liver, kidney, lung, skin, and nasal tissue (Cashman et al, 1996). Additional literature documents the presence of CarbEs in many human tissues and fluids, including brain, milk, mammary gland, pancreas, small intestine, colon. 

A temporary rise in plasma glucose concentration immediately follows a meal, but within 2-3 hours the level returns to the preprandial level. Several factors influence the blood glucose profile. 

Log D is the log distribution coefficient at a particular pH. This is not constant and will vary according to the protogenic nature of the molecule. Log D at pH 7.4 is often quoted to give an indication of the lipophilicity of a drug at the pH of blood plasma. Figures 8-10 show the distribution profiles of various acids and bases. 

Fiehn, O. and Kind, T., Metabolite profiling in blood plasma, Methods Mol. Biol., 358, 3, 2007. 

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