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 TNX-102 2.4 mg SL Tablets (a new formulation of cyclobenzaprine designed to result in increased dosage precision and decreased potential for morning grogginess) at 2.4 mg and 4.8 mg and to compare the bio-availability of TNX-102 2.4 mg SL Tablets at 2.4 mg and 4.8 mg to that of TNX-102-A 2.4 mg SL Tablets (without phosphate) at 2.4 mg and cyclobenzaprine (5 mg tablets).

Inclusion Criteria:

• Healthy adults
• Male or female
• Non-smoker
• 18-65 years old
• 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.