What incompatibility occurs when cyclizine lactate is mixed with Palladone (hydromorphone hydrochloride) 2 mg/ml solution for injection or infusion in 0.9% saline?

Cyclizine lactate precipitates when mixed with Palladone (hydromorphone hydrochloride) 2 mg/ml solution for injection or infusion in 0.9% saline; water for injection is the recommended diluent, with sufficient dilution needed to avoid precipitation.