Abstract
Multilayer tablet of tramadol hydrochloride was developed for the treatment of osteoarthritis. Multilayer tablet was comprised of immediate release layer, followed by drug-free retardant layers on either side of middle matrix layer. The sustained release effect was achieved by exploring the polysaccharide of tamarind kernel seed of Tamarindus indica. An extracted polysaccharide showed high swelling index and viscosity. Three-layer tablet system was optimized based on central composite design of two factors each at three levels, considering the amount of drug-free retardant layers, on either side (100 mg) of middle matrix drug polysaccharide layer (210 mg). Multilayer tablet was evaluated for hardness, thickness and drug content. Drug release is characterized by an initial rapid release (54% in acidic media), followed by a slow and again a second phase of relatively rapid release for 10 h. Presence of rat cecal content (2% and 4% w/v) in dissolution medium released the drug at a faster rate. Thus, inexpensive and abundantly available tamarind seed polysaccharide can be a good choice of polymer for dual release of multilayer tablet for arthritis patients.
Keywords: Immediate release, matrix tablet, multilayer tablet, tamarind seed xyloglucan polysaccharide, three-layer tablet, tramadol hydrochloride.
Graphical Abstract