Chemical stability and adsorption of succinylcholine chloride injections in disposable plastic syringes.

The purpose of these investigations was to determine the stability and adsorption behaviour of succinylcholine chloride (SCC) when stored in plastic syringes. Drug degradation was monitored using the USP high-pressure liquid chromatography method. Solutions containing 20 mg/ml of SCC in 5% dextrose, and in normal saline, were studied at 5, 25 and 40 degrees C. The hydrolysis of SCC in i.v. fluids followed apparent zero-order kinetics. The manufacturer's recommended expiry period was found to be too conservative. If protected from light, storage at room temperature for up to 3 months can be safely recommended, without significant loss of chemical stability. However, microbiological quality assurance will need to be implemented and an appropriate shelf-life assigned on the basis of both microbiological and chemical stability data.