Fat emulsion as a vehicle for diazepam. A study of 9492 patients

Conventional preparations of diazepam for i.v. use contain solvents which cause pain on injection and thrombophlebitis in a high percentage of cases. However, diazepam can be dissolved with advantage in the oleaginous phase of an oil-in-water emulsion (Diazemuls). Diazemuls has been given to 9492 patients without serious side-effects. Following i.v. injection, 2435 patients were studied with respect to pain and clinical effect. Only 0.4% experienced pain. The intended clinical effect was recorded in 99% of the patients. I.m. injection of Diazemuls resulted in a significantly smaller frequency of pain in connection with the injection than did the injection of Valium (7% and 43% respectively). Pharmacokinetic studies have been made after i.v. and i.m. injection of Diazemuls and Valium. The distribution and elimination phases after i.v. injection were the same with both forms. Thus the drug probably quickly separates from the oil particles of the emulsion after injection. After i.m. administration, the plasma concentration shows a wide spread with both preparations. A brief survey of other substances tested in emulsion form is presented.