Oxyetylenated rape oil methyl esters as auxiliary substances modifying pharmaceutical availability of non-steroid anti-inflammatory substances fom solid oral dosage forms. Part 1. Pre-formulation research. Rofams, oxyethylenated methyl esters of rape oil acid, constitute a new class of surface active agents, which exhibit high surface activity and, due to the process of micellar solubilization, can improve solubility, and hence, positively influence the pharmaceutical availability of the drugs of group II of the Biopharmaceutical Classification System. The present study involves pre-formulation research into the solubilizing properties of Rofams with respect to diclofenac.