Preparation and physicochemical characterization of a spray-dried lornoxicam self-microemulsifying system

The solubility of lornoxicam in liquid self-microemulsifying drug delivery system (SMEDDS) containing different amounts of tromethamine was determined.The carrier for spray drying was selected from lactose,sucrose and mannitol and its appropriate amount was optimized.The obtained spray-dried lornoxicam self-microemulsifying powder was characterized by particle size,morphology,dissolution and rheological behavior.The appropriate amount of tromethamine was 10 mg/g and the solubility of lornoxicam was enhanced to be 23.8 mg/g.The suitable carrier for achieving the spray drying process was mannitol with the weight ratio of 1∶1 to liquid SMEDDS.The spray dried SMEDDS powder was nearly spherical powder with good self-microemulsifying properties.The reconstituted emulsion was determined to be a plastic non-Newtonian fluid with the particle size of about 120 nm.The solid spray-dried lornoxicam self-microemulsifying system had significantly higher dissolution than lornoxicam tablets in three media and its dissolution profile was demonstrated to be rapid and pH-independent.