Used as a reference standard in analytical testing to ensure accurate quantification of itraconazole in pharmaceutical formulations and biological samples. Commonly employed in HPLC and other chromatographic methods for quality control, stability studies, and bioequivalence testing. Helps maintain compliance with regulatory requirements by verifying the identity, purity, and concentration of itraconazole in drug products. Also used in research settings to develop and validate analytical methods for antifungal agents.