HPLC Method Measures ALS Drug Combination in Plasma

Amyotrophic lateral sclerosis (ALS), often known as Lou Gehrig's disease, is a serious condition that gets worse over time. Recently, scientists have proposed combining two existing drugs (the anti-inflammatory celecoxib [CLX] and the antibiotic ciprofloxacin [CPR]) as a possible new treatment for ALS and other similar brain and nerve diseases.

Researchers at the Pharmaceutical Analytical Chemistry Department of Alexandria University (Egypt) set out to create and test simple, sensitive, eco-friendly, and affordable laboratory methods for measuring both celecoxib and ciprofloxacin at the same time, whether the drugs were in raw powder form, laboratory-made tablets, or blood plasma. To do this, the researchers developed two different ultraviolet (UV) detection methods, plus one method using liquid chromatography. The first UV method works by directly measuring how much light each drug absorbs; ciprofloxacin is measured at one specific wavelength, while celecoxib is measured at a wavelength chosen because it's a point where the readings for both drugs cross over and don't interfere with each other. The second UV method uses a more advanced mathematical technique to tease apart the two drugs' signals, allowing each one to be measured accurately at its own separate wavelength. On top of these two methods, the researchers also built a reversed-phase high-performance liquid chromatographic (HPLC) method using a specialized column and a carefully fine-tuned solvent mixture to physically separate the two drugs from each other before measuring them, using two different types of detectors to confirm and accurately quantify both. A paper based on this work was published in the journal Scientific Reports.¹

What is ALS?

ALS is a fast-moving, irreversible disease that destroys motor neurons, causing progressive muscle weakness and physical dependence while typically sparing the mind. Increasingly viewed as a complex, whole-body condition rather than a purely motor disorder, this reframing is driving new research into early detection, molecular-level understanding, and targeted therapies aimed at slowing (or even reversing) nerve damage.^2,3

Why Develop New Methods to Measure CLX and CPR Together?

Since no existing spectrophotometric or chromatographic methods exist for measuring CLX and CPR together (only a fluorescence-based method has been reported)⁴, the researchers saw a clear opportunity to develop novel, sensitive, cost-effective, and practical methods to fill this gap.¹

How Well Do the Newly Developed Methods for Measuring CLX and CPR Perform?

The researchers validated their methods for this study against international guidelines, confirming strong accuracy, precision, and sensitivity. The two light-based (spectrophotometric) methods offer fast, affordable, eco-friendly options, one using a special "crossover" wavelength and the other using advanced math to separate the two drugs' overlapping signals. A complementary chromatography-based method, using a specialized column and dual detectors, proved highly effective at separating and measuring both drugs even in complex samples like blood plasma, making it well-suited for monitoring drug levels in patients. Finally, using a comprehensive green chemistry scoring system, the researchers confirmed all the methods are both environmentally sustainable and highly practical for real-world use.¹

Are These New Methods Accurate, Reliable, and Environmentally Sustainable Enough for Practical Use?

The methods the researchers developed were successfully tested on laboratory-made tablets and blood plasma samples. To make sure the results were accurate, they fine-tuned how the samples were prepared beforehand, which helped reduce interference from other substances in the mix and improved how much of each drug they were able to recover and measure.¹

When the researchers checked how well these methods performed, the results were excellent: the methods reliably tracked drug concentration across the full range tested, and were accurate, consistent, selective (meaning they could correctly tell the two drugs apart from other substances), and sensitive enough to detect small amounts. Altogether, this confirms these methods are dependable enough to use for routine quality testing and for analyzing drug levels in biological samples like blood.¹

Finally, the researchers also evaluated how environmentally friendly and practical these methods were, using a standardized scoring system designed to assess both performance and sustainability. The results showed that these methods are not just accurate and reliable; they are also a genuinely green and practical choice for measuring celecoxib and ciprofloxacin going forward.¹

References

1. Aboukhalil, F. M.; Khamis, E. F.; El-Sayed, M. A. et al. Green Analytical Methods for Quantification of a New Combination Therapy for Amyotrophic Lateral Sclerosis: Assessment by EPPI Framework. Sci Rep. 2026, 16 (1), 26178. DOI: 10.1038/s41598-026-66936-w
2. Kiernan, M. C.; Vucic, S.; Cheah, B. C. et al. Amyotrophic Lateral Sclerosis. Lancet 2011, 377 (9769), 942-955. DOI: 10.1016/S0140-6736(10)61156-7
3. Miller, R. G.; Appel, S. H. Introduction to Supplement: The Current Status of Treatment for ALS. Amyotroph. Lateral Scler. Frontotemporal Degeneration 2017, 18 (s1), 1–4. DOI: 10.1080/21678421.2017.1361447
4. Ahmed, A. B.; Draz, M. E.; Asad, H. et al. Innovative Synchronous Spectrofluorometric Method for Assessing a Novel Drug Combination in Amyotrophic Lateral Sclerosis: In Vivo Human Application With Greenness and Sustainability Evaluation. Luminescence 2025, 40 (6), e70222. DOI: 10.1002/bio.70222