An open-label study to assess the pharmacokinetics (PK), pharmacodynamics (PD), safety, and tolerability of epinephrine administered as a single dose of DESF in pediatric subjects weighing ≥30 kg with a personal history of allergic reactions and are at high risk for serious allergic reactions. All treated participants will receive a single dose of DESF on Study Day 1. On Study Day 2, participants will return to the study site for an Oral Mucositis Assessment Scale (OMAS) assessment.

This is a Phase 1, multi-site, open-label, single treatment study conducted in male and female pediatric subjects (age 7-17 years) who have a have a personal history of allergic reactions and are at high risk for serious allergic reactions. This study is designed to evaluate the pharmacokinetics (PK) of epinephrine administered as a single dose of DESF.

Up to 24 DESF treated pediatric participants are expected to be enrolled. The study population will consist of healthy, non-smoking, pediatric male and female participants aged 7 through 17 with a known history of allergic reactions that the investigators believe continue to remain at high risk of serious allergic reactions (e.g., anaphylaxis).

All treated participants will be administered a single, 12 mg, dose of DESF on Study Day 1. No other investigational product will be administered.

The expected maximum duration of an individual's participation in this study will be, approximately, 32 days including a 30-day Screening Period, a 1-day Treatment Period (Study Day 1) and a 1-day (±1 day) Post-treatment Follow-up (Study Day 2).

Inclusion Criteria:

• Male and female children ages 7 through 17 years of age at the start of the Screening Period.
• Participants with a known history of allergic reactions with an active prescription for epinephrine, and who (in the judgement of the investigator) are at high risk for serious allergic reactions (e.g., anaphylaxis).
• Participant has a body weight ≥30 kg (66 lbs).
• Participant is within the 5th and 95th percentiles, inclusive, for weight by age (according to CDC growth charts).

Exclusion Criteria:

• Any current or past medical conditions such as significant systemic diseases that, in the investigator's opinion, might significantly affect pharmacodynamic responses to DESF.
• Concurrent clinically significant cardiovascular, hematological, renal, neurologic, hepatic, endocrine, psychiatric, or malignant diseases.
• Known intolerance or hypersensitivity to any component of DESF.
• Participant has a disease or condition known to interfere with the absorption, distribution, metabolism, or excretion of DESF.
• Positive urine drug screen, saliva alcohol test, or urine cotinine test at Screening or prior to administration of DESF on Study Day 1.
• Participant has participated in any clinical investigation within the 30 days prior to the planned administration of DESF on Study Day 1.