A Randomized, Open-label, Crossover Study to Evaluate the Comparative Bioavailability, Pharmacokinetics, and Safety of GTX-102 Administered as an Oral Spray Compared to Intramuscular Injection - betamethasone and an Oral Solution of Betamethasone in Healthy Subjects.

Four groups of subjects will receive 2 treatments each and randomized in 2-way crossover.

Inclusion Criteria:

1. Healthy male and female subjects between the ages of 18 and 55 years, inclusive.
2. Willing and able to provide written informed consent prior to participating in the study.
3. Able to communicate clearly with the Investigator and staff; able to read, complete questionnaires, and understand study procedures.
4. Able to complete all screening period evaluations, and stay in the clinic testing facility for up to 2 consecutive days on 2 separate occasions.
5. Body mass index (BMI) between 18 and 32 kg/m2, inclusive, and body weight between 40 and 120 kg, inclusive.

Exclusion Criteria:

1. Has a history of or current clinically significant medical illness including (but not limited to) pulmonary, cardiovascular, coagulation disorders, lipid abnormalities, gastrointestinal, immunologic, endocrine (stable thyroid hormone replacement therapy is not excluded), neurologic, psychiatric, or thromboembolic disease, metabolic disturbances, or any other current physical condition that the Investigator considers should exclude the participant, or that could interfere with the interpretation of the study results.
2. Has current or recent (within 6 months) history of gastrointestinal disease, or any surgical or medical condition such as Crohn's disease or liver disease, that could potentially alter the absorption, metabolism, or excretion of the study drug.
3. Has any clinically significant medical condition, physical examination finding, vital signs, ECG abnormality (at screening), or clinically significant abnormal value for hematology, serology, clinical chemistry, or urinalysis at screening or at admission to the study center, as deemed appropriate by the Investigator