AbstractThe physicochemical stability of an admixture of ipratropium bromide and salbutamol nebuliser solutions, 1:1 v/v, was determined by storing solutions for five days in a refrigerator at 4C, at 22C protected from light and at 22C under 24 hour fluorescent lighting. Concentrations of ipratropium and salbutamol were periodically determined using a high performance liquid chromatography assay. The nebuliser solution admixtures retained greater than 90 per cent of their original concentrations of ipratropium and salbutamol for the duration of the study. Differences in losses between storage conditions were not statistically significant.Admixtures of proprietary ipratropium bromide and salbutamol nebuliser solutions (1:1 v/v) retain greater than 90 per cent of their initial concentrations if stored between 4C and 22C for periods of up to five days. An expiry period of five days for these admixtures would seem reasonable in practice.