What is a white oval pill IP189 on one side and 375 on the other side?

The pill imprinted with "IP 189" on one side and "375" on the other is identified as Diphenhydramine Hydrochloride 25 mg, which is an antihistamine commonly used to relieve symptoms of allergy, hay fever, and the common cold. It can also be used as a sleep aid due to its sedative effects. Always consult a healthcare professional before taking any medication.