Co-Crystal

A crystalline material composed of two or more different molecules (typically a drug and a co-former) in a defined stoichiometric ratio within the same crystal lattice, held together by non-covalent interactions such as hydrogen bonds. Co-crystals can improve solubility, dissolution rate, stability, and mechanical properties of a drug without altering its chemical identity, offering advantages over salt forms for non-ionizable compounds.

Exemples

• Sacubitril-valsartan (Entresto): co-crystal of sacubitril and valsartan in 1:1 ratio
• Ertugliflozin-L-pyroglutamic acid co-crystal with improved solid-state stability
• Caffeine-oxalic acid co-crystal used in early co-crystal research as a model system