The stability of metoclopramide hydrochloride (0.5 mg/mL) in 0.9% sodium chloride injection in polypropylene syringes was studied at 25 deg C, using a stability-indicating high-performance liquid chromatographic assay method. The concentrations of the drug were directly related to peak heights, and the percent relative standard deviation based on five injections was 1.4. The drug decomposed when treated with sodium hydroxide or hydrochloric acid, and the products of decomposition did not interfere wiht the assay procedure. the injection did not lose any potency after 21 days of storage at 25 deg C, and the pH value of 5.0 did not change. The physcial appearance of the injection remained clear throughout the study period.