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This background material explains the theory behind the log P and log D calculation: Introduction. Symbols used. Definition of logP and logD. Example. Partition and distribution coefficients. Relation between macro and micro partition coefficients. LogP calculation methods. Examples for logP and logD calculations.
6 sty 2024 · LogD = LogP − log (1 + 10 (pH − pKa) δ i) where δ i = {1, − 1} for acids and bases, respectively. The astute reader will notice that only a single pKa is provided here which is the global pKa. In Figure 4 I show how the LogD varies with pH for two acidic and two basic drugs.
To solve a logarithmic equations use the esxponents rules to isolate logarithmic expressions with the same base. Set the arguments equal to each other, solve the equation and check your answer.
log D is the logarithm of the distribution coefficient. Definition of log P and log D. The partition coefficient is the ratio of the concentration of the compound in octanol to its concentration in water.
12 sty 2019 · Of particular interest is the log D at pH = 7.4 (the physiological pH of blood serum). Applications like Marvin allow the user to calculate the logD but also display the pH distribution profile, as shown below for Warfarin.
Our calculation method takes into account the effect of the counterion concentration on log D and log P . Symbols used. Throughout the document we use the following symbols: Pi (upper case) is the macro partition coefficient, where subscript i refers to the ionization state of species included in Pi, e.g. i= -2, -1, 0, +1, +2.
Here is a LogD cheat sheet created from their work, summarizing how much affinity is expected from a change based on lipophilicity considerations alone. For a methyl group for example, the median LogD change is about 0.3, indicating that you'd expect about a 2-fold increase in lipophilic potency due to the methyl group's contribution to LogD.
