Conversations with Michael Dong: What Is a Basic Drug?

Michael Dong, editor of LCGC International's "Perspectives in HPLC" column, has launched a video series in 2026 called "HPLC in Pharmaceutical Analysis," which explores how the technique is used in the pharmaceutical field.

In celebration of National Chemistry Week at the end of October, ChromatographyOnline.com is pleased to share "Conversations with Michael Dong" this month, featuring highlights from the series. We encourage readers to watch the full series, a free and thorough educational introduction to HPLC for pharmaceutical laboratory professionals at every stage of their careers who want to brush up on the basics. No matter how much experience you have with the technique, you're sure to come away with useful tips for sharpening your skills.

In this installment, Dong discusses “basic drugs.” What are they? Why are most drugs basic rather than acidic?

Basic drugs contain nitrogen-containing functional groups, such as amines, that can accept a proton and carry a positive charge. A large share of small-molecule drugs fall into this category. Nitrogen-containing groups play a central role in how a drug binds to its biological target, and the ability to form salts helps developers improve solubility and stability.

In HPLC, basic analytes interact with residual silanol groups on silica-based columns, causing peak tailing and poor resolution. Understanding an analyte's acid–base behavior is a key first step in selecting the right column and mobile-phase pH.

The entire video, “Why are most small-molecule drugs weak bases?” can be accessed at https://www.youtube.com/watch?v=jSRIEXYAdyM&t=7s

Michael W. Dong is a principal of MWD Consulting, which provides training and consulting services in HPLC and UHPLC, method improvement, pharmaceutical analysis, and drug quality. He was formerly a Senior Scientist at Genentech, a Research Fellow at Purdue Pharma, and a Senior Staff Scientist at Applied Biosystems/PerkinElmer. He holds a PhD in Analytical Chemistry from City University of New York. He has more than 130 publications and a bestselling book in chromatography. He is an editorial advisory board member of LCGC North America and the Chinese American Chromatography Association. Direct correspondence to: LCGCedit@mmhgroup.com.