By using techniques to explore latent variable space and probe the physicochemical properties of each excipient and how they correlate with anti-aggregation activity, hypotheses on the design of novel excipients with greater APR SASA shielding, and therefore improved performance as anti-aggregation agents, can be postulated. Particularly, variable importance in projection (VIP) plots are used in feature selection in drug design 91 and are a useful tool in investigating the structure-activity relationship within a PLS model by indicating the critical descriptors that explain the maximal variance in both dependent and independent variables.