A complexation process between a cyclodextrin and active pharmaceutical ingredients is disclosed, and comprises a process for prepg. a complex of at least one cyclodextrin and at least one active pharmaceutical ingredient comprising the steps of: a. Prepg. a first soln. (soln. A) comprising at least one cyclodextrin and at least one solvent; b. Prepg. a second soln. (soln. B) comprising at least one dissolved, partially dissolved or suspended API; c. Mixing said soln. A and soln. B by means of a microfluidization system to produce a soln. and/or suspension of at least one of said complex; d. Isolating said soln. and/or suspension and/or optionally drying it; and e. Optionally collecting a powd. form of the complex.  The described process has high throughput with higher yields of complexation in less time than prior art methods.  The complexes obtained by the invention are characterized by having enhanced dissoln. and/ or bioavailability of the active pharmaceutical ingredient in body fluids.