This is a single-center, randomized, single-dose, active-controlled study in healthy male and female subjects.

The study will enroll subjects to evaluate the PK of 3 dose strengths (50 mg, 100 mg and 200 mg) of GTX-101 compared to Subcutaneous injection in healthy adult subjects.

Blood samples for PK assessments will be collect at specified time points. Safety assessments will also be performed throughout the study.

Inclusion Criteria:

• Provision of signed and dated informed consent form (ICF)
• Healthy adult male or female, aged 18 to 55 years, inclusive, at Screening
• Body mass index (BMI) within 18.0 kg/m2 to 30.0 kg/m2, inclusively at Screening
• Have no clinically significant diseases captured in the medical/surgical history or evidence of clinically significant findings on the physical examination (including vital signs), weight and/or clinical laboratory tests and/or ECG, as determined by an Investigator

Exclusion Criteria:

• History of significant hypersensitivity to bupivacaine, local anesthetic agents of amide type, or any related products (including excipients of the formulations) as well as severe hypersensitivity reactions (like angioedema) to any drugs
• Presence of significant gastrointestinal, liver or kidney disease, or any other conditions known to interfere with the absorption, distribution, metabolism or excretion of drugs or known to potentiate or predispose to undesired effects
• History of significant gastrointestinal, liver or kidney disease that may affect drug bioavailability