Sandoz Diphenhydramine Hydrochloride Injection is a sterile, clear, colourless aqueous solution containing 50 mg/mL diphenhydramine hydrochloride. The formulation includes sodium hydroxide or hydrochloric acid to adjust pH and water for injection. Intended for intramuscular or intravenous administration by healthcare professionals, it comes in a convenient 10 x 1 mL pack. DIN 00596612. No prescription required in Canada; prescription required in Quebec.