Aqueous solubility log

Two approaches to quantify/fQ, i.e., to establish a quantitative relationship between the structural features of a compoimd and its properties, are described in this section quantitative structure-property relationships (QSPR) and linear free energy relationships (LFER) cf. Section 3.4.2.2). The LFER approach is important for historical reasons because it contributed the first attempt to predict the property of a compound from an analysis of its structure. LFERs can be established only for congeneric series of compounds, i.e., sets of compounds that share the same skeleton and only have variations in the substituents attached to this skeleton. As examples of a QSPR approach, currently available methods for the prediction of the octanol/water partition coefficient, log P, and of aqueous solubility, log S, of organic compoimds are described in Section 10.1.4 and Section 10.15, respectively. 

Using such dielectric-based predictions, when the methanol-apparent solubility, log Sq versus wt% methanol is extrapolated to 0% cosolvent, the aqueous solubility, log So, can be estimated when log S(0 is extrapolated to 100% cosolvent, the membrane solubility, log iS cm, can be estimated. The approximate membrane partition... 

Approximately 300 drugs were tested in aqueous solubility, log D, and apparent permeability assays. Compounds having low values for solubility, or apparent permeability, or extreme log D values were flagged. The frequency of compounds with flags in each human absorption (%) bin is shown. 

The ADME portion of the BioPrint profile is made up of a panel of in vitro assays chosen for their potential to predict in vivo pharmacokinetics (Table 2). Some of the in vitro assays measure properties that contribute to the in vivo bioavailability of the new drug candidate. These include aqueous solubility, log D (octanol), and log D (cyclohexane), physico-chemical... 

A screening of the virtual combinatorial library was performed in several steps. As potential extractants must be insoluble in the water phase, the ISIDA-Log S module incorporating QSPR models for aqueous solubilities (log S)95 has been used for filtering the library. Thus, the compounds for which log S < -3 were considered insoluble in water other compounds were excluded. A subset containing 9,306 potentially insoluble molecules has been screened using the structure-log D models. The main goal of screening was the selection of potentially efficient extractants. However, in... 

The aqueous solubilities (-log S) of mono- through decaCDEs (106 PCDE congeners) range between 4.21 mol 1 1 and 12.95 mol 1 1 [59]. These values were calculated from high performance liquid chromatography (HPLC) data at 30°C. PCDEs are more soluble in water than PCBs, which have extremely low water solubilities. The water solubilities of PCBs range from 7 x 103 pg 1 1 to 0.02 pg 1 1 [3]. 

F. Experimentally determined aqueous solubility log data for 2868 molecules at 25°Ca... 

The preference for similar polarities could also be attributed to similar solubilities of co-crystal formers. Most co-crystals in the CSD were prepared as single crystals grown from solution, and similar co-former solubilities make finding the right conditions for single crystal growth easier. However, the lack of correlation in descriptors usually associated with aqueous solubility (Log P, polar surface area) suggests that solubility is not the decisive factor behind the preferred similarity of polarity descriptors. 

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