ACD/Solubility DB

What's New

Version 4.5 to 5.0

ACD/Solubility DB 5.0 includes experimental solubility measurements for over 4000 neutral compounds and weak electrolytes. These data have been accumulated over the past twenty five years by Professor Sam Yalkowsky (College of Pharmacy, University of Arizona), and represents the world's largest and most expertly curated database of aqueous solubility data. Careful attention has been paid to the experimental conditions and the extent of ionization for each compound in order to ensure that the values cited are true intrinsic Solubilities.

In the past, ACD/Labs prediction of aqueous solubility has followed Yalkowsky's well regarded General Solubility Equation (GSE). With Solubility DB 5.0, a training set of over one thousand weak electrolytes was identified, new parameters were introduced, and compounds were grouped into broad classes. For each class, a separate extension of the GSE was created to improve accuracy and move beyond some compound class specific limitations of the approximations with the GSE. As a result, general accuracy is improved, and the sensitivity to the melting point is reduced. One specific class of compounds for which accuracy has improved drastically are zwitterions.

ACD/Solubility DB 5.0 prediction algorithm has been improved in the following ways:

• The following parameters are used in correlation equations: LogP/LogD, MW, MolVol, HydBonding (number of H-acceptors).
• Different equations are used for different classes of compounds.
• Prediction is less sensitive to the Melting Point presence for many classes of compounds. Even information such as whether the compound is a solid or liquid at room temperature is useful in the prediction.
• The accuracy is better for many different classes, especially for zwitterions (improved, in some cases, by 2-3 orders of logS).
• Includes a database of measured intrinsic solubilities and references of over 4,400 compounds.

• Database can be viewed in Tile or Single Record display.

• You can select what parts of database reference you want to be displayed:

• ACD/Solubility DB predicts intrinsic solubility for neutral form of compound.
• Predicts the pH and solubility that can be observed when adding pure compound to unbuffered water:

• It reports solution proportion of each ionic form as a function of pH:

 
Solubility of non-Zwitterions

Solubility of Zwitterions

Version 4.0 to 4.5

Version 4.5 of ACD/Solubility brings an improved algorithm for prediction of solubility to your desktop. The following table summarizes the solubilities (mg/L) of selected compounds and compares experimental values with those calculated using versions 4.0 and 4.5 of ACD/Solubility. Please note that in every case the experimental melting point as stated was used (unless "liq") appears.