Spectrophotometric determination of metoclopramide hydrochloride in pure and pharmaceutical preparations

Metoclopramide-HCl reacts with 2-naphthol - 3,6-disulphonic acid and sodium nitrite to give an orange color after heating for 45 s at 100 degree C, having maximum absorbance at 490 nm. The reaction is selective for metoclopramide-HCl with 0.01 mg/10ml as visual limit of identification and provides a basis for a new spectrophotometric determination. The reaction obeys Beer's Law from 0.01 mg to 2.5 mg/10ml of metoclopramide-HCl and the relative standard deviation is 0.74%. The quantitative assessment of tolerable amount of other drugs is also studied. (author)