HPLC Analysis of Pseudoephedrine and Citric Acid on Zodiac HST- S3 Column

Pseudoephedrine, a basic hydrophilic drug commonly found in cough and cold formulations, is often preserved with citric acid, a hydrophilic acidic compound. Using the Zodiac HST S3 column, these two compounds are effectively separated through a combination of HILIC, cation-exchange, and anion-exclusion mechanisms. Detection is performed by UV. This method serves as a robust, generic approach for analyzing pseudoephedrine and other hydrophilic drugs and preservatives in pharmaceutical mixtures.