This study presents a rapid, sensitive, and straightforward approach to measure chlorpheniramine maleate (CPM) by using turbidity CFIA. The method involves CPM reacting with sodium nitroprusside (Nitropress) to produce a pale white precipitate. The NAG-SSP-5S1D analyzer was used to measure turbidity at 0°–180° angle to detect the attenuation of incident light as a result of collision on the surfaces of the precipitate particles. The linear range of CPM measurements was between 0.008 and 11 m.mol/L, with correlation coefficient of 0.9983 and R2% = 99.65. The limit of detection was determined to be 0.0328 µg/sample from the lowest concentration in the calibration curve, and the repeatability of the method (RSD%) was less than 0.4% (n = 6) for the selected concentration (10–13 m.mol/L). The method was successfully applied for the determination of CPM in various drugs by using the standard addition method. The developed method and the classical method (UV spectrophotometry at λmax= 265 nm and turbidity) were compared using t-test. No significant difference was observed among the three methods at 95% confidence level. Overall, the developed flow injection method offers simplicity, sensitivity, and reliable analytical performance for the determination of CPM. This method can be used as an alternative for the analysis of CPM in drugs compared with the reference method
