Why is a large partition coefficient important?
The blood:gas partition coefficient is an important determinant of the speed of anesthetic induction and recovery. It describes the partition of an agent between a gaseous phase, such as alveolar air, and the blood. The greater the blood:gas partition coefficient, the greater the solubility in blood.
What does a partition coefficient tell you?
The partition coefficient is the measure of the lipophilicity of a drug and an indication of its ability to cross the cell membrane. It is defined as the ratio between un-ionized drug distributed between the organic and aqueous layers at equilibrium.
How does partition coefficient affect diffusion?
The higher the partition coefficient, the greater the oil solubility of the solute, and the more readily it will dissolve in the lipid bilayer of cell membranes and be transported by simple diffusion.
What is a good logP value?
around 2
A drug targeting the central nervous system (CNS) should ideally have a logP value around 2;2 for oral and intestinal absorption the idea value is 1.35–1.8, while a drug intended for sub-lingual absorption should have a logP value >5. Not only does logP help predict the likely transport of a compound around the body.
How do I lower my partition coefficient?
Changing the Partition Coefficient K can be lowered by changing the temperature at which the vial is equilibrated or by changing the composition of the sample matrix. In the case of ethanol, K can be lowered from 1355 to 328 by raising the temperature of the vial from 40°C to 80°C.
What does high LogP mean?
A negative value for logP means the compound has a higher affinity for the aqueous phase (it is more hydrophilic); when logP = 0 the compound is equally partitioned between the lipid and aqueous phases; a positive value for logP denotes a higher concentration in the lipid phase (i.e., the compound is more lipophilic).
Does partition coefficient vary with concentration?
Partition coefficient is the ratio of concentrations of a compound in a mixture of two immiscible phases at equilibrium. Since it is a ratio the drug will get distributed according to its partition coefficient hence it will not depend on the concentration of the drug.
What is logD vs LogP?
logD is a log of partition of a chemical compound between the lipid and aqueous phases. LogP is equivalent to logD for non-ionisable compounds and represents the partition of the neutral form for ionizable compounds (and, hence, is a virtual, unmeasurable, property).
What is a good logD value?
According to this rule, the successful drug candidate should possess LogP value not greater than 5. LogD is a distribution coefficient widely used to measure the lipophilicity of ionizable compounds, where the partition is a function of the pH. Reliable measurable range is approximately -1 to 4.5.
What is effect of concentration of solute on partition coefficient?
As expected, the partition coefficients decreased with increasing agarose concentration and with increasing macromolecular size. Moreover, increasing the BSA concentration increased the partition coefficient of BSA itself and that of all four Ficolls. This effect was most pronounced for the largest test solutes.