Improving the Solubility of Lenalidomide via Cocrystals

An anticancer drug, lenalidomide,
has low oral bioavailability
(below 33%) due to its poor solubility in water. To improve its solubility,
three cocrystals of lenalidomide with urea (1) and 3,5-dihydroxybenzoic
acid (2, 3) were prepared. The structures
of 1–3 were determined by single
crystal X-ray diffraction, and they all form three-dimensional hydrogen-bonded
frameworks between lenalidomide and the coformers. The apparent solubility
value and intrinsic dissolution rate of lenalidomide in phosphate
buffer of pH 6.8 have been improved after the formation of cocrystals.
In addition, 2 and 3 can convert to each
other under certain conditions.