The solutions of dobutamine hydrochloride (5 mg/ml), dopamine hydrochloride (4 mg/ml), nitroglycerin (1 mg/ml) and sodium nitroprusside (1 mg/ml) in dextrose 5% injection were stable for 24 h when stored at 25 degrees C in 60-ml plastic syringes. For sodium nitroprusside, the syringes must be wrapped with aluminium foil (provided by the manufacturer), otherwise the loss in potency is very high (22%). There was no change in the pH values of dobutamine and dopamine solutions as well as sodium nitroprusside solutions in the prewrapped syringes. However, the pH value of nitroglycerin solutions decreased to 4.3 from 4.6 and that of sodium nitroprusside solutions in unwrapped syringes from 4.2 to 3.5; these solutions had discoloured. The chromatogram also showed new peaks from the products of decomposition. The physical appearances of the other solutions did not change.

No abstract

The chemical stability of thiopental sodium injection (2.5%) when stored at 25 degrees and 5 degrees in disposable plastic syringes of two manufacturers (Monoject and Becton Dickenson and Co.) has been studied using the USP-NF method. The injection appeared to be stable for five days at 25 degrees and 45 days at 5 degrees with a loss in potency of less than 7%. The thiopental sodium did not adsorb on the syringes. The pH values and the physical appearance did not change. An additional peak was obtained in the chromatogram from both the freshly prepared and the assay solution probably due to an impurity in the powder.

The chemical stabilities of isoetharine hydrochloride inhalation solution, metaproterenol sulphate inhalation solution and terbutaline sulphate injection, after diluting 1 in 10 with sodium chloride 0.9% injection were studied. On storing the solutions in amber-coloured syringes, they were stable for at least 120 days at 5 degrees C. At 25 degrees C they were also stable for 120 days except that isoetharine solution discoloured and lost 7.8% of its potency after 90 days of storage. There was a new peak in the chromatogram from the decomposition product. All other solutions remained clear for 120 days at both temperatures. The initial and final pH values were similar except that after 120 days at both temperatures. The initial and final pH values were similar except that after 120 days at 25 degrees C, the pH value of terbutaline solution had increased from 4.9 to 5.4.