In order to obtain the region where a homogeneous and stable system could be achieved, a pseudoternary phase diagram (showed in Fig. 1) was built following these steps: first, it was prepared a fixed ratio (1:15 in mass) of lubricating oil/AVK. Different ratios for these two components were tested, from 1:1 to 1:16 (in mass). Theminimumratio that allowed the formation of three-component solution was 1:15. This mixture (oil/AVK) was treated as if it was only one component in the diagram, which has three components in its vertices: oil/AVK, water and n-propanol. Second, the points inside the triangle were plotted, as follows: fixing the quantity of one component and varying the others (the variations were 5% for each). The procedure ended when the whole interior of the diagram was plotted. Each point represents amixture and, therefore, it must have its proper physical characteristics (emulsified or transparent mixture) identified for further delineation of the different regions. Fig. 1 shows two distinct regions: region I, where a homogeneous and transparent solution is found, and region II, where mixtures form an emulsion.