The invention relates to the compounds of formula I and formula II or its pharmaceutical acceptable salts, as well as polymorphs, solvates, enantiomers, stereoisomers and hydrates thereof. The pharmaceutical compositions comprising an effective amount of compounds of formula I or formula II, and methods for treating or preventing or modulating moderate to severe pain in a disease may be formulated for oral, buccal, rectal, topical, transdermal, transmucosal, intravenous, parenteral administration, syrup, or injection. Such compositions may be used to treatment of pain, severe pain, chronic pain, chemotherapy induced pain, epilepsy, glaucoma, arthritis, tooth aches, inflammation, musculoskeletal pain, sciatica, radiculopathy pain, migraine, neuropathic pain, post herpetic neuralgia, neuralgia pain, multiple sclerosis, multiple sclerosis, restless legs syndrome (RLS), cluster headache, depression, fibromyalgia, amyotrophic lateral sclerosis (ALS), convulsions, partial seizures, mood-stabilizing agent and bipolar disorder.