Search results
Results From The WOW.Com Content Network
FDPB-based methods calculate the change in the pK a value of an amino acid side chain when that side chain is moved from a hypothetical fully solvated state to its position in the protein. To perform such a calculation, one needs theoretical methods that can calculate the effect of the protein interior on a p K a value, and knowledge of the pKa ...
This example shows a good agreement between the published value a=2.6*10 −3 and the calculated value a=2.59*10 −3 at the smallest given mole fraction of 0.00861 but at higher concentrations of propionic acid the value of an increases considerably, showing deviations from the predicted value.
In pharmacokinetics, the drug accumulation ratio (R ac) is the ratio of accumulation of a drug under steady state conditions (i.e., after repeated administration) as compared to a single dose. The higher the value, the more the drug accumulates in the body. An R ac of 1 means no accumulation.
The Henderson–Hasselbalch equation relates the pH of a solution containing a mixture of the two components to the acid dissociation constant, K a of the acid, and the concentrations of the species in solution. [6] Simulated titration of an acidified solution of a weak acid (pK a = 4.7) with alkali
Therefore, the dose required to give a certain plasma concentration can be determined if the V D for that drug is known. The V D is not a physiological value; it is more a reflection of how a drug will distribute throughout the body depending on several physicochemical properties, e.g. solubility, charge, size, etc.
In pharmacokinetics, a loading dose is an initial higher dose of a drug that may be given at the beginning of a course of treatment before dropping down to a lower maintenance dose. [1] A loading dose is most useful for drugs that are eliminated from the body relatively slowly, i.e. have a long systemic half-life.
[c] [2] For example, a hypothetical weak acid having K a = 10 −5, the value of log K a is the exponent (−5), giving pK a = 5. For acetic acid, K a = 1.8 x 10 −5, so pK a is 4.7. A higher K a corresponds to a stronger acid (an acid that is more dissociated at equilibrium).
Values for the parameters β (0), β (1) and C for inorganic and organic acids, bases and salts have been tabulated. [16] Temperature and pressure variation is also discussed. One area of application of Pitzer parameters is to describe the ionic strength variation of equilibrium constants measured as concentration quotients.