AQUAFAC 3: aqueous functional group activity coefficients; application to the estimation of aqueous solubility

AQUAFAC is a group contribution approach for estimating the aqueous activity coefficients of organic compounds. The present study derives 44 new group contribution values. These group values are based on 970 different organic compounds representing over 2,432 individual sohibility measurements. Ten fold cross validation of the present AQUAFAC model gives an average root mean square error of 0.448 log units. In addition, the AQUAFAC group values are used to estimate the aqueous solubility of a diverse set of organic compounds. It is shown to be modestly more accurate than the conventional octanol/water (log P) method, giving average absolute standard errors of 0.41 and 0.61, respectively