This multi-site Phase 3 clinical trial is a randomized, double-blind, placebo-controlled study to identify the safety and efficacy of DPI 386 nasal gel (intranasal scopolamine gel) for the prevention and treatment of nausea associated with motion sickness. The study will be conducted aboard military ships undergoing military operations or aboard commercial boats rented for the study to obtain data in a real world environment. The study will have three arms: DPI-386 nasal gel, placebo nasal gel, and Transderm Scop® (1.0 mg/72 hours; transdermal scopolamine patch [TDS], the current standard of care for the treatment of motion sickness). The study will include 120 subjects per arm, for a total of 360 subjects (n=360). A double-dummy design will be used to mask the treatment assignment. All subjects will receive both a patch and nasal gel: DPI-386 Nasal Gel + placebo patch, placebo nasal gel + placebo patch, or TDS patch + placebo nasal gel.

Inclusion Criteria:

• 1. Provision of signed and dated Informed consent document (ICD). 2. Stated willingness to comply with all study procedures and availability for the duration of the study.

  3. Male or female, aged 18 to 59 (inclusive). 4. Tricare health insurance beneficiary. All potential subjects must be able to provide a current military Identification (ID) or Department of Defense (DOD) dependent ID to be viewed by the research staff prior to signing the ICD.

  5. At least minimally susceptible to provocative motion as evidenced by a minimum score of 3.0 on the MSSQ.

  6. In good general health as evidenced by medical history with no recent history or current diagnosis of clinical problems as assessed by the research staff.

  7. Ability to take intranasal medication and willingness to adhere to the study schedule and time constraints.

  8. For females of child-bearing potential: willingness to provide a urine sample for the hCG pregnancy test during the Screening Visit and each day of the Treatment Period. Test must be negative or the subject will be excluded from the study. Note: Women of non-childbearing potential are defined as those who are non-surgically sterile (i.e., without menses for at least 12 consecutive months) or surgically sterile (i.e., those who underwent a hysterectomy with or without oophorectomy, fallopian tube ligation, and endometrial ablation).

  9. Agreement to adhere to the following lifestyle compliance considerations:

  1. Refrain from consumption of grapefruit and any substance containing grapefruit for seven days prior to, during, and for seven days after the Treatment Period.

  2. Abstain from alcohol for 24 hours prior to first dose of study medication and during the Treatment Period.

  3. Note: there will be no restriction on caffeine or nicotine use during the study; however, the actual use of these substances will be recorded as part of the CEBQ.

     Exclusion Criteria:

• 1. Pregnancy, lactation, or positive urine pregnancy test at any time. 2. Known allergic reactions to any drugs. 3. Currently prescribed any of the following medication types: any form of scopolamine (including Transderm Scop®) within 5 days, belladonna alkaloids within 2 weeks, antihistamines (including meclizine) within 2 weeks, tricyclic antidepressants within 2 weeks (depending on reason taken), muscle relaxants and nasal decongestant within 4 days of Module 1.

  4. Hospitalization or significant medical event (to include childbirth) within the past six months.

  5. Treatment with another investigational drug or other intervention within the past 30 days.

  6. Having donated blood or plasma or suffered significant blood loss within the past 30 days.

  7. Having any of the following medical conditions within the last two years or if any of the following medical conditions were experienced more than two years ago and are deemed clinically significant by the PI or Study Physician:

  1. Any known drug allergies and/or severe year-round environmental allergies.
  2. Significant gastrointestinal disorder, asthma, or seizure disorders.
  3. History of vestibular disorders.
  4. History of narrow-angle glaucoma.
  5. History of urinary retention problems.
  6. History of alcohol or drug abuse.
  7. Nasal, nasal sinus, or nasal mucosa surgery.

Double Blinded