Use of ultrasound to prepare lipid emulsions of lorazepam for intravenous injection.

Lipid emulsions can be used as a vehicle for the production of low-volume injectable preparations with minimally water-soluble active ingredients. First, we focus on the galenic and technological conditions established by ultrasound techniques. A 2(5) factorial design was used to optimize the carrier emulsion. The study then deals with the development of a parenteral emulsion formulation for lorazepam (1 mg/ml), which is compared with the highest concentration (0.05 mg/ml) achieved in the optimal aqueous diluent for lorazepam (dextrose 5% in water). The physical and chemical stability of lorazepam in the emulsion was examined for 7 months.