Abstract The present research was aimed to design controlled release suspension formulation of BCS class I drug Tramadol hydrochloride a centrally acting synthetic analgesic. Complexes of indion 244 ion-exchange resin and tramadol hydrochloride, a model drug, were prepared using a batch method. The prepared resinate complexes were microencapsulated by o/o solvent evaporation technique. These microcapsules were then formulated into the suspension dosage form to get the controlled release of drug for extended period. The resinate microcapsule suspensions were evaluated for the flow properties, drug content and in vitro drug release. Dry powder suspensions shown excellent flow properties and the in vitro drug release showed a significant sustained drug release up to 12 hours. The stability studies were performed as per ICH guidelines for the dry and hydrated forms of suspensions. The results obtained clearly evident that the dry powder suspensions are best suitable for the storage conditions and gives better physical and chemical stability.
Keywords Tramadol hydrochloride, ion exchange resin, controlled release, suspension.