The conclusions we reached after analyzing the bibliography for this review are as follows

CDs are excipients widely used by the pharmaceutical industry that are incorporated in many pharmaceutical formulations marketed in several regions of the world. In recent decades, the development of multicomponent systems has increased the potential for CDs to not only to enhance drug solubility, dissolution and bioavailability, but to also allow the modulation of other drug properties, such as the stability and biological activity. The multicomponent complexes of CD with organic acids or bases, amino acids and polymers have proven to be very useful for improving and controlling properties of ionizable, weakly ionizable and non-ionizable drugs. In general, the most suitable auxiliary agent and the most appropriate CD should be selected by considering the particular drug’s physicochemical properties and the characteristics to optimize. For example, in the case of acidic drugs, the basic auxiliary agent TEA has been demonstrated to significantly enhance both the solubility and the permeability. Regarding using amino acids as auxiliary agents, arginine is the most used compound, since in general it shows a synergistic effect with the CD toward enhancing drug solubility. In summary, our analysis of the available literature showed the interest in multicomponent CD complexes as approaches with which to improve the therapeutic efficacy of drugs.