(2003; 67 pages)
2.1.2 Method for the assay of chloroquine tablets
The content of chloroquine was determined by UV-spectrophotometry in accordance with an adapted method for chloroquine phosphate tablets of the USP 24. The method consists of recording the UV absorbance of the sample at a wavelength of 343 nm and comparing it to the absorbance of a reference standard in a concentration range representing a 100% label claim at the same wavelength.
The method was adapted in such a way that it was possible to determine the quantity of the different salt forms of chloroquine in the tablets, where applicable. As all USP methods are specific for the analyte, the method was only validated in terms of precision. Interference from excipients was validated by superimposing the UV spectra of the sample and standard.
No interference from excipients was noted, and the precision of the method was %RSD < 2.