Cyclodextrin Complexation as a Way of Increasing the Aqueous Solubility and Stability of Carvedilol

We studied the effect of several CDs on carvedilol's solubility and chemical stability in various aqueous media. Our present results show that it is possible to achieve a carvedilol concentration of 5 mg/mL (12.3 mM) in the presence of 5 eq of gamma CD or RAMEB in an aqueous medium with an acceptable acid pH (between 3.5 and 4.7). Carvedilol formed 1:1 inclusion complexes but those with RAMEB appear to be stronger (K = 317M(-1) at 298 K) than that with gamma CD (K = 225M(-1) at 298 K). The complexation of carvedilol by RAMEB significantly increased the drug's photochemical stability in aqueous solution. These results might constitute a first step towards the development of a novel oral formulation of carvedilol.

Automated summary

The study found that it is possible to achieve a high concentration of carvedilol in the presence of gamma CD or RAMEB in aqueous media, with RAMEB showing stronger inclusion complexation and significantly increasing the drug's stability. These results could be a first step in developing a novel oral formulation of carvedilol.