Double-blind study comparing the pharmacokinetics, safety and tolerability of morphine administered subcutaneously (SC) with and without human recombinant hyaluronidase (HYLENEX) and intravenously conducted in patients in a hospice care setting or through a palliative care medicine setting. In this within-patient controlled study, each eligible study patient receives a single injection by each of the three methods of morphine administration, sequentially on three consecutive days, according to the order specified by a randomization schedule.