Pharmacokinetic Evaluation of Intranasal Nalmefene

Open-label, randomized, 2-period, 2-treatment, 2-sequence, crossover study in 68 healthy volunteers. Subjects will be assigned to each of the 2 possible sequences. Each subject will receive 2 treatments during the 2 dosing periods: Intranasal (IN) dose of 3 mg nalmefene hydrochloride and intramuscular (IM) dose of 1.0 mg nalmefene, with a 4 day washout period between doses. Screening can occur up to 28 days before baseline admission, subjects will then stay in the inpatient facility for 7 days to complete the treatment phase of the study and will be discharged following completion of the discharge procedures at the end of the last period. Subjects will be called 3 to 5 days after discharge to inquire concerning Adverse Events (AEs) and concomitant medications since discharge.