A high performance liquid chromatography (HPLC) method for Poloxamer 188 using size-exclusion chromatography (SEC) was developed and two different detection mechanisms, evaporative light scattering (ELSD) and electrospray ionization mass spectrometry (ESI-MS), were compared for their quantification capabilities in itraconazole formulation. Both detection techniques coupled with SEC separation were highly effective for the determination of Poloxamer 188, which is difficult to analyze by other common HPLC methods. As expected, ESI-MS detection provided sensitivity and selectivity superior to ELSD. But since the analyte is an excipient in the formulation, high sensitivity was not required and ELSD's simplicity and ruggedness made it more appropriate for routine analysis of this formulation.