2H-​Benzimidazol-​2-​one, 1-​[1-​(cyclooctylmethyl)​-​1,​2,​3,​6-​tetrahydro-​5-​(hydroxymethyl)​-​4-​pyridinyl]​-​3-​ethyl-​1,​3-​dihydro-​, hydrochloride (1:1)