Co-crystallization brings new opportunities for preformulation and is a first step towards crystal engineering. Indeed, where traditional approaches such as salt screening fail, co-crystallization often still manages to solve the crystallization problems or improve a drug substance’s physicochemical properties. The Crystal16® offers a systematic and effective method to discover new stable co-crystal forms based on easy-to-measure solubility data of the pure components.
The Crystal16® can be used to design a co-crystal screening program by measuring the clear points of a series of co-builders and the API. The possibility for co-crystallization can be checked by measuring the saturation temperature of the mixtures, based on the individual components’ solubilities.
Check out our example of co-crystallization between carbamazepine (CBZ) with iso-nicotinamide (INA). The experiments illustrate that a systematic screening method can be applied to investigate several combinations of API, co-builders and solvents, optimizing the probability of discovering co-crystalline materials. Matching solution with co-crystal stoichiometry should be set aside, and co-crystal screening should be designed based on easily accessible pure component solubilities.