Very low dose (VLD) cyclobenzaprine at bedtime has shown promise as a treatment for fibromyalgia, but the chemistry of cyclobenzaprine requires new formulation technology for bedtime use. The present trial is designed to assess the safety and tolerability of 3 different formulations of TNX-102 2.8 mg SL Tablets (a new formulation of cyclobenzaprine designed to result in increased dosage precision and decreased potential for morning grogginess) and to compare the bio-availability of 3 different formulations of TNX-102 2.8 mg SL Tablets (TNX-102 with potassium phosphate, TNX-102-B with sodium phosphate, and TNX-102-C with trisodium citrate) to that of cyclobenzaprine (5 mg tablets).

Inclusion Criteria:

• Healthy adults
• Male or female
• 18-65 years old
• Non-smoker
• BMI > 18.5 and < 30.0
• With medically acceptable form of contraception (female only)
• With signed informed consent

Exclusion Criteria:

• Any clinically significant abnormality including ECG abnormalities or vital sign abnormalities (systolic blood pressure < 90 or > 140 mmHg,
• Diastolic blood pressure lower < 50 or > 90 mmHg, or heart rate < 50 or > 100 BPM)
• Any abnormal laboratory test (including positivity for Hep B, Hep C, HIV, and
• Hemoglobin < 128 g/L (males) or < 115 g/L (females) and hematocrit < 0.37 L/L (males) or < 0.32 L/L (females))
• History of alcohol or drug abuse or dependence within 1 year and/or positive drug, cotinine, or alcohol tests
• Use of any drug (within 30 days), supplement, or food (within 14 days) known to induce or inhibit hepatic drug metabolism prior to study medication
• Positive pregnancy test, breastfeeding or lactating
• Use of medication other than hormonal contraceptives or topical products, including OTC, natural health products, MAO inhibitors
• Participation in an investigational study within 30 days prior to dosing
• Donation of plasma (within 7 days), or donation or loss of blood of 50-499 mL (within 30 days), or of > 499 mL (within 56 days) prior to dosing.