Determination of Chlorpromazine Hydrochloride in Troches by Spectrophotometry

In the HOAc-NaOAc buffer solution with pH of 5.50, chlorpromazine hydrochloride reacted with Fe(Ⅲ) and Chromazurol S to form blue ternary complexes with the maximum absorption at the wavelength of 660 nm. When the concentration of Fe(Ⅲ) and Chromazurol S was constant, linear relationship was found between the absorbance and the mass concentration of chlorpromazine hydrochloride in the range of 0.20-20 mg·L-1, with detection limit (3s/k) of 0.058 mg·L-1. The method was used to detect the content of chlorpromazine hydrochloride in tablet samples, giving recovery rates measured by standard addition method in the range of 97.8%-98.5% and RSDs (n=5) in the range of 1.1%-1.5%.