Purpose: To develop a rapid and cost effective spectrofluorimetric method for the assay of chloroquine phosphate tablets.
Methods: Spectrofluorimetric assays of chloroquine phosphate tablets were done in dilute acids and following extraction in chloroform. Results obtained were compared statistically with the official UV/VIS spectrophotometric method. Method A comprises direct spectrofluorimetric assay of chloroquine tablets in 0.05 M H2S04 and method B involves prior extraction of chloroquine base in chloroform.
Results: The accuracy of determination of chloroquine phosphate tablets in 0.05M H2SO4 was similar to the official USP XXII spectrophotometric method (P>0.05). Other solvents of comparison were water and 0.1NHCl. There was no obvious advantage in extracting chloroquine into chloroform prior to analysis (P> 0.05) as recommended in the USP. Judging from the stoke’s shift, true fluorescence was also found with 0.05M H2SO4. The assays were linear over the concentration range of 1-10 μg/ml in 0.05M H2SO4 with a limit of detection of 0.77μg/ml. The percent recoveries of 100.76 ± 1.60 and 101.24 ±0.77% were obtained following assay of chloroquine without extraction and after extraction with chloroform, respectively. Dilute sulphuric acid (0.05M) was found to give the best correlation between fluorescence intensity and concentration of chloroquine phosphate.
Conclusion: the spectrofluorimetric method developed is rapid and simple and could find application as a cost-effective technique for the assay of chloroquine phosphate tablets.