Availability of isosorbide dinitrate, diazepam and chlormethiazole, from i.v. delivery systems.

The loss of isosorbide dinitrate from aqueous solutions stored in plastic infusion bags and/or infused through plastic giving sets was investigated. During simulated infusions, the loss of isosorbide dinitrate was found to be flow-rate dependent. The clinical and pharmacokinetic significance of this loss is discussed. Infusion o isosorbide dinitrate from a glass syringe through high density polyethylene tubing overcame the loss associated with its administration via plastic infusion bags and intravenous giving sets. This method was also applied successfully to minimise the previously reported loss of diazepam and chlormethiazole during infusions.