Formulating and stability of benzodiazepines in a new lipid emulsion formulation

The objective of the current study was to evaluate the novelty of a new lipid emulsion formulation containing 30% oil phase as a drug delivery system. Therefore different benzodiazepines (BZs), namely diazepam, tetrazepam, clonazepam and lorazepam, were incorporated into this emulsion formulation. This lipid emulsion formulation showed enhanced solubilization capacity as 10 mg/ml, 10 mg/ml, 0.9 mg/ml, and 1.8 mg/ml formulations for diazepam, tetrazepam, clonazepam, and lorazepam were achieved, respectively. Incorporating the drugs into the lipid emulsion did not alter its physicochemical properties. Also the free and the drug emulsion formulations displayed good physical stability after autoclaving and after around one year of storage at shelf, as no changes in the physicochemical properties were observed. Most drugs also showed stable behavior after autoclaving and after approximately 1 year of storage at shelf. The only exception was lorazepam, as only around 50% of the drug was still intact after autoclaving.