Development and Evaluation of Extended Release Formulation of Tramadol Hydrochloride Based on Osmotic Technology

Extended release formulation of Tramadol Hydrochloride based on osmotic technology was developedand evaluated. Target release profile was selected and different variables were optimized to achieve it.Formulation variables such as osmotic agent, plasticizer and coating thickness of semi-permeablemembrane were found to markedly affect drug release. Tramadol hydrochloride release was directlyproportional to the level of osmogent and plasticizer but inversely proportional to the level of coatingthickness of semi-permeable membrane. Drug release from developed formulation was independent ofpH and agitation intensity but dependent on osmotic pressure of release media. The optimizedformulation was compared with marketed product CONTRAMAL SR and accelerated stability studywas also carried out for 6 months.