Patent ID: 8507468

Claim:
A method of increasing a concentration of a diazepam in an aqueous, single phase, multi-component solvent system, comprising: increasing a water concentration in the multi-component solvent system to at least 15% by volume such that the concentration of the diazepam is at least 30 mg/ml; and wherein the components of the solvent system are selected such that the step of increasing the water concentration allows the diazepam to remain chemically stable and substantially completely dissolved in the system at room temperature over a period of at least 24 hours; and wherein the multi-component solvent system is selected from the group consisting of (a) N-methylpyrrolidone in an amount of about 15 vol %, ethanol in an amount of about 50 vol %, and PEG-200 in an amount of about 20 vol %, (b) N-methylpyrrolidone in an amount of about 20 vol %, ethanol in an amount of about 45 vol %, and PEG-200 in an amount of about 15 vol %, (c) N-methylpyrrolidone in an amount of about 20 vol %, ethanol in an amount of about 45 vol %, and PEG-200 in an amount of about 17.5 vol %, (d) N-methylpyrrolidone in an amount of about 50 vol %, ethanol in an amount of about 0 vol %, and PEG-200 in an amount of about 50 vol %, (e) N-methylpyrrolidone in an amount of about 35.2 vol %, ethanol in an amount of about 25.1 vol %, and PEG-200 in an amount of about 5.0 vol %, and (f) N-methylpyrrolidone in an amount of about 30.1 vol %, ethanol in an amount of about 30.1 vol %, and PEG-200 in an amount of about 5.0 vol %.