Novel pharmaceutical composition of bradykinin potentiating penta peptide with β-cyclodextrin: Physical–chemical characterization and anti-hypertensive evaluation

This work describes chemical properties and anti-hypertensive activity of an oral pharmaceutical formulation obtained from the complexation of β-cyclodextrin (β-CD) with bradykinin potentiating penta peptide (BPP-5a) founded in the Bothrops jararaca poison. Physical chemistry characterizations were recorded in order to investigate the intermolecular interactions between species in complex. Circular dichroism data indicated conformational changes of BPP-5a upon complexation with β-CD. ROESY and theoretical calculations showed a selective approximation of triptophan moiety into cavity of β-CD. Isothermal titration calorimetry data indicated an exothermic formation of the complex, which is accomplished by reduction of entropy. The anti-hypertensive activity of the BPP-5a/β-CD complex has been evaluated in spontaneous hypertensive rats, showing better results than pure BPP-5a.