New Cocrystals of Antipsychotic Drug Aripiprazole: Decreasing the Dissolution through Cocrystallization.

Cocrystallization is an important route to tuning the solubility in drugs development, including improving and reducing. Five cocrystals of aripiprazole (ARI) with resveratrol (RSV) and kaempferol (KAE), ARI-RSV, ARI2-RSV1·MeOH, ARI-KAE, ARI-KAE·EtOH, ARI-KAE·IPA, were synthesized and characterized. The single crystal of ARI2-RSV1·MeOH, ARI-KAE·EtOH, and ARI-KAE·IPA were analyzed by single crystal X-ray diffraction (SCXRD). The SCXRD showed multiple intermolecular interactions between API and the coformers, including hydrogen bond, halogen bond, and π-π interactions. Dissolution rate of the two nonsolvate ARI-RSV and ARI-KAE cocrystals were investigated through powder dissolution experiment in pH = 4.0 acetate buffer and pH = 6.8 phosphate buffer. The result showed that RSV could reduce the dissolution rate and solubility of ARI in both medium through cocrystallization. However, KAE improved the dissolution rate and solubility of ARI in pH = 4.0 medium, on the contrary, the two solubility indicators of ARI were both reduced for ARI-KAE cocrystal.

Two Novel Palbociclib-Resorcinol and Palbociclib-Orcinol Cocrystals with Enhanced Solubility and Dissolution Rate.

Palbociclib (PAL) is an effective anti-breast cancer drug, but its use has been partly restricted due to poor bioavailability (resulting from extremely low water solubility) and serious adverse reactions. In this study, two cocrystals of PAL with resorcinol (RES) or orcinol (ORC) were prepared by evaporation crystallization to enhance their solubility. The cocrystals were characterized by single crystal X-ray diffraction, Hirshfeld surface analysis, powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared and scanning electron microscopy. The intrinsic dissolution rates of the PAL cocrystals were determined in three different dissolution media (pH 1.0, pH 4.5 and pH 6.8), and both cocrystals showed improved dissolution rates at pH 1.0 and pH 6.8 in comparison to the parent drug. In addition, the cocrystals increased the solubility of PAL at pH 6.8 by 2-3 times and showed good stabilities in both the accelerated stability testing and stress testing. The PAL-RES cocrystal also exhibited an improved relative bioavailability (1.24 times) than PAL in vivo pharmacokinetics in rats. Moreover, the in vitro cytotoxicity assay of PAL-RES showed an increased IC50 value for normal cells, suggesting a better biosafety profile than PAL. Co-crystallization may represent a promising strategy for improving the physicochemical properties of PAL with better pharmacokinetics.