To develop formulations for effective management of chronic pain without side effects associated with NSAIDs and COX-2 antagonists, Tramadol hydrochloride, an opioid antagonist, was encapsulated within Gelatin microspheres for controlled delivery for longer periods. The microspheres were prepared using a single emulsion technique and were investigated. Tramadol hydrochloride could be encapsulated into Gelatin microspheres with an entrapment efÞ ciency of 97.2%. Spherical, transparent, and free-ß owing microspheres were obtained. Scanning electron microscopy revealed the spherical structures under the magniÞ cation of 200 µm. The FTIR and DSC analysis indicated the stability and compatibility of the drug in gelatin microspheres. The microspheres were in the suitable particle size range of 20 to 160 µm. The drug was released continuously for a period of 12 hrs with a maximum release of 99.79%.
Key words: Gelatin, microspheres, tramadol HCL, sesame oil.
