The invention relates to the compounds of formula 1 or its pharmaceutical acceptable salts, as well as polymorphs, solvates, enantiomers, stereoisomers and hydrates thereof The pharmaceutical compositions comprising art effective amount of compounds of formula &Idigr；； and methods for treating or preventing moderate to severe pain, may he formulated for oral, buccal, rectal, topical, transdermal, transmucosal, intravenous, parenieral adminisiration, syrup, or injection. Such compositions may be used to treatment of muscle pain, spasticity, neuropathic pain, fibromyalgia, postoperative pain,.muscle spasticity, headache, chronic pain, sub-chronic pain and local pain.
