Collander relationship

Collander Relationship between 2% DOPC and 20% Soy Intrinsic Permeabilities... 

Figure 7.44 Collander relationship between intrinsic permeabilities of 20% soy lecithin versus 2% DOPC PAMPA models.

It is known that the RPLC retention parameters are often strongly correlated to the analyte s distribution coefficient in organic solvent/ water. Generally, the relationship between liquid/liquid (LL) distribution and RPLC retention are of the form of the dimensionless Collander-type equations, e.g., see Eq. (15.21)... 

Roberts et al. criticized the attempts to predict permeabilities since permeability is the result of two processes, partitioning and diffusion [40], Therefore, instead of following the approach of Potts and Guy, Roberts et al. tried to find a predictive model for each of these processes separately. For the partitioning step they found a Collander-type linear relationship (Eq. 11) between the logarithms of the stratum corneum-water and the octanol-water partition coefficients with a high correlation coefficient (r2 = 0.839) ... 

Coffander-iype Relationships Collander has studied partition coefficients in different alcohol-water systems [16]. He found that these partition coefficients are mutually correlated. For certain compounds containing one hydrophilic group, such as alkanols, alkanoic acids, alkanoates, dialkyl ethers, and alkylamines and selected compounds containing two, three, or four such groups, he reports the following equation ... 

Muller s Relationship Muller [17] derived the following collander-type relationship for the monohydrophilic class of alkanols (C2-C6) ... 

Over 20 years ago Collander (2) showed that there was a linear relationship between the log F values measured in any two alcohol/ water systems. 

Partition coefficients from different solvent systems can also be compared and converted to the octanol/water scale, as was suggested by Collander (116). He stressed the importance of the following linear relationship log 2 = a logPj + b. This type of relationship works well when the two solvents are both alkanols. However, when two solvent systems have varying hydrogen bond donor and acceptor capabilities, the relationship tends to fray. A classical example involves the relationship between log P values in chloroform and octanol (117,118). 

The presumed relationships between partitioning in different solvent/water systems (organic phases A and B) according to the Collander equation (1951)... 

The consideration of bioconcentration as an interphase distribution between aqueous and organic phases governed by diffusion processes anticipates a potential parallelism with partitioning processes between other non-miscible phases. Direct relationships between the partition coefficients in different systems (water/organic phases A and B, respectively) were recorded by Collander (1951) ... 

Partition Coefficients - In using an aqueous phase and a simple organic solvent to serve as a reference system for approximating hydrophobic interactions in biochemical systems, Collander has pointed out that we are assuming log Pi = a log P2 + b. In this relationship Pi is the partition coefficient in one system (fatty and aqueous biophases) and P2 is the partition coefficient in a second system (e.g., octanol-water). While Collander did provide some evidence for this linear relationship, much... 

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