Cephalon, Inc. has signed an agreement to acquire the North American rights to Amrix (cyclobenzaprine hydrochloride extended-release capsules) from ECR Pharmaceuticals for $100 million cash. ECR is eligible to receive future cash payments based on the achievement of certain milestones. The FDA approved two dosage strengths of Amrix (15 mg and 30 mg) in February 2007 for short-term use as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful muscu...