Cyclobenzaprine HCl Extended Release 15 mg Versus Placebo in Treatment of Cervical and/or Lower Back Pain Due to Muscle Spasms of Local Origin

Inclusion Criteria:

1. In the opinion of the investigator, the participant is capable of understanding andcomplying with protocol requirements.

2. Signs and dates a written, informed consent form and any required privacyauthorization prior to the initiation of any study procedures.

3. Is experiencing for no more than 14 days cervical or lower back pain (as assessed bythe participant) due to muscle spasms (confirmed by the physician) associated withacute, painful musculoskeletal conditions.

4. Is male or female and aged 18 to 50 years, inclusive.

5. Female participants require to be either 2 years postmenopausal or surgically sterileby bilateral tubal ligation, hysterectomy, or bilateral oophorectomy, or, ifpremenopausal, had to be using an approved contraceptive method.

6. Female participants of child-bearing potential must have a negative urine humanchorionic gonadotropin (hCG) test result for pregnancy at study entry.

7. After signing the informed consent form, the participant agrees not to make changes todietary, exercise, or smoking habits and not to enter a weight loss program duringhis/her participation in the study.

Exclusion Criteria:

1. Has muscular pain secondary to acute trauma or fractures (e.g., due to osteoporosis).Such conditions could have been ruled out based on medical history, x-ray, or physicalexamination.

2. Has received any investigational compound within 30 days prior to Screening.

3. If female, the participant is pregnant or lactating or intending to become pregnantbefore, during, or within 1 month after participating in this study; or intending todonate ova during such time period.

4. Has a history of drug abuse or recent (within the last 12 months) history of excessivealcohol consumption defined as >2 drinks/day (>90 ml of 80 proof alcohol orequivalent).

5. Has mild, moderate, severe liver impairment.

6. Is an immediate family member, study site employee, or is in a dependent relationshipwith a study site employee who is involved in conduct of this study (eg, spouse,parent, child, sibling) or may consent under duress.

7. Takes any concomitant medication including over-the-counter and herbal products formuscle spasms. If a participant is taking such medications, the medications has to bediscontinued before starting the study.

8. Takes or took within last 14 days medications, such as:

9. selective serotonin reuptake inhibitors (SSRIs);

10. serotonin norepinephrine reuptake inhibitors (SNRIs);

11. tricyclic antidepressants (TCAs);

12. monoamine oxidase (MAO) inhibitors;

13. tramadol;

14. bupropion;

15. meperidine;

16. verapamil;

17. non-steroid anti-inflammatory drugs (NSAIDs);

18. topical anti-inflammatory medications

19. Has a history or clinical manifestations of significant medical condition, such as:

20. hyperthyroidism;

21. acute recovery phase of myocardial infarction;

22. arrhythmias, heart block or conduction disturbances;

23. congestive heart failure;

24. angle-closure glaucoma;

25. urinary retention;

26. increased intraocular pressure.

27. Has abnormal physical findings or a medical condition that might have placed theparticipant at risk or interfered with the participant's ability to participate in thestudy.

28. Has any known condition or disorder that might have affected absorption of the studydrug.

29. Has a history of hypersensitivity or allergies to cyclobenzaprine and/or tricyclicantidepressants or any of their components.

30. Has a history of hypersensitivity to any NSAIDs including salicylate sensitivity.

31. Has a history of thrombocytopenia.

32. Has a history of gastro-intestinal bleeding, cerebrovascular bleeding or otherbleeding disorders.

33. Had active or history of recurrent peptic ulcer/haemorrhage (two or more distinctepisodes of proven ulceration or bleeding)

34. Has a history of severe renal impairment

35. Had a major surgery during the 6 months preceding study entry.

36. Has a language barrier or any other problems precluding good communication orcooperation.

37. Has any reason to believe that he/she would not be able to complete the evaluationsneeded in this study.

38. Has a known history of positive screen for hepatitis B surface antigen, hepatitis Cantibody, or human immunodeficiency virus (HIV) antibody.

39. Drug abuse in anamnesis.