Novel Salt-Cocrystals of Berberine Hydrochloride with Aliphatic Dicarboxylic Acids: Odd–Even Alternation in Physicochemical Properties

In this study, various structurally
similar aliphatic dicarboxylic
acids, namely, succinic acid, glutaric acid, adipic acid, and pimelic
acid, were employed as coformers to obtain phase pure cocrystals with
berberine chloride (BCl) by a slow solvent evaporation method. The
structures of the four novel salt-cocrystals of BCl were determined
by single crystal X-ray diffraction analysis and their solid-state
properties were characterized. Compared with BCl·2H2O, all the cocrystals showed a higher melting point, improved powder
dissolution and intrinsic dissolution rate (IDR), and lower hygroscopicity.
It is noteworthy that the melting points and IDRs of these cocrystals
exhibit an odd-even alternation with the carbon chain length of the
acids.