Ruboxistaurin is a drug that is used to treat diabetic retinopathy and other related eye conditions. It is important to ensure that the drug is pure and free from any impurities that can affect its efficacy and safety. Ruboxistaurin impurities can include substances such as residual solvents, degradation products, and other impurities that are formed during the manufacturing process. It is essential to identify and control these impurities to ensure the quality and safety of the drug. This can be achieved through rigorous testing and monitoring of the drug during the manufacturing process and throughout its shelf life.