Blue sandoz pill with 663 what is it?

The blue Sandoz pill imprinted with "663" is identified as Diphenhydramine Hydrochloride 25 mg. Diphenhydramine is an antihistamine commonly used to relieve symptoms of allergy, hay fever, and the common cold. It can also be used as a short-term treatment for insomnia or to prevent nausea and vomiting. Always consult a healthcare professional before using any medication.