“…Response surface methodologies, such as mixture designs, have recently been used in the formulation of microemulsions (ME) [ 25 , 26 , 27 ], self-emulsifying drug delivery systems (SEDDS) [ 28 , 29 , 30 ], liposomes [ 31 , 32 ] and tablets [ 19 , 33 , 34 , 35 , 36 , 37 , 38 ]. The D-optimal design is one of the most used methodologies in this field, because it allows different composition constraints, in which the sum of all components is constant (100% w / w ).…”