Formulation of intravenous carbamazepine emulsions by SolEmuls technology.

Oil in water (O/W) emulsions for parenteral nutrition can be employed as intravenous (i.v.) carriers for drugs that are poorly soluble in water and in oil by localising the drug in the interfacial lecithin layer, e.g. Amphotericin B emulsions. By now, the emulsion production required organic solvents. SolEmuls technology localises the drug in the interfacial layer by a solvent-free high-pressure homogenisation process. SolEmuls was applied to produce Carbamazepine emulsions at increasing drug concentrations from 0.5 to 10mg/ml. Drug powder and Lipofundin emulsion were mixed and homogenised at 1500bar. Characterisation of emulsions and short-term stability were performed by photon correlation spectroscopy (PCS) and laser diffractometry. Drug incorporation (absence of non-dissolved drug crystals) was investigated by light microscopy and a centrifugation test. The emulsions were physically stable and complete drug dissolution is possible up to 3mg/ml. Up to 10mg/ml drug hybrid dispersions of emulsion droplets and ultrafine nanocrystals were obtained. Both, emulsions and hybrid dispersions are suitable as i.v. injectables regarding size and stability.