Improving Biopharmaceutical Properties of Vinpocetine Through Cocrystallization

Vinpocetine is a poorly water soluble weakly basic drug (pK_a = 7.1) used for the treatment of several cerebrovascular and cognitive disorders. Because existing formulations exhibit poor bioavailability and scarce absorption, a dosage form with improved pharmacokinetic properties is highly desirable. Cocrystallization represents a promising approach to generate diverse novel crystal forms and to improve the aqueous solubility and in turn the oral bioavailability. In this article, a novel ionic cocrystal of vinpocetine is described, using boric acid as a coformer, and fully characterized (by means of differential scanning calorimetry, solid-state nuclear magnetic resonance, powder and single-crystal X-ray diffraction, and powder dissolution test). Pharmacokinetic performance was also tested in a human pilot study. This pharmaceutical ionic cocrystal exhibits superior solubilization kinetics and modulates important pharmacokinetic values such as maximum concentration in plasma (C_max), time to maximum concentration (t_max), and area under the plasma concentration-time curve (AUC) of the poorly soluble vinpocetine and it therefore offers an innovative approach to improve its bioavailability.