Determination of the Hansen solubility parameters from solubility data using an improved evaluation approach, the concentric spheroids method
Máté Mihalovits
Abstract
A new evaluation method for the determination of the Hansen solubility parameters of a considered substance is suggested in this paper. The earlier proposed gradient binary mixture method is to be conducted to obtain solubility data on a continuous scale (e.g. mg/ml) rather than the widely used soluble/insoluble dichotomous response. Using the continuous responses, Hansen spheroids can be fitted with any given radius, allowing the concentric spheroids model to be fitted to the experimental data. The common center of the spheroids is the estimate of the Hansen solubility parameters of the considered substance. The new suggested desirability function fits this mathematical problem and takes the continuous nature of the data into account. A simulation study was also carried out, which implies that the approach presented in this paper results in more precise estimates of the solubility parameters than the presently used method.