Green Chemistry Meets Quality by Design in New HPTLC Method for Kidney Drug Desidustat

Anemia linked to chronic kidney disease remains one of the most stubborn complications in modern medicine, quietly eroding quality of life and raising cardiovascular risk for millions of patients worldwide. At the heart of the problem lies a molecular failure: damaged kidneys produce less erythropoietin, the hormone that commands the bone marrow to manufacture red blood cells. A newer generation of oral drugs, known as hypoxia-inducible factor prolyl hydroxylase inhibitors, has begun to change that picture by coaxing the body into restarting its own erythropoietin production. One of the most prominent of these agents is desidustat, marketed as Oxemia and developed by Zydus Cadila in India. But as with any medicine that reaches large patient populations, the question of how to measure it accurately, cheaply, and sustainably in pharmaceutical products has become just as important as the drug itself.

A team of researchers at Gujarat Technological University in Gandhinagar, India, has now delivered what they describe as the first analytical method for desidustat that is simultaneously green, statistically optimized, and capable of tracking the drug’s degradation. Writing in the journal Discover Green Chemistry, the group led by Parmar Bharvi and Kashyap Thummar combined two frameworks that have been reshaping pharmaceutical analysis: Analytical Quality by Design, often abbreviated AQbD, and the principles of Green Analytical Chemistry. Their chosen tool was high-performance thin-layer chromatography, or HPTLC, a planar chromatographic technique that has long been prized for its low solvent consumption, high sample throughput, and modest operating costs, but which has traditionally been developed through trial and error rather than systematic design.

The scientific logic behind the study begins with risk. In an AQbD workflow, the analyst first defines an Analytical Target Profile, essentially a specification sheet for what the method must achieve, and then identifies every factor that could jeopardize those goals. The team used failure mode and effects analysis, a technique borrowed from engineering, to score potential failure causes by severity, likelihood, and detectability, producing risk priority numbers that ranked each variable. Mobile phase volume, chamber saturation time, and solvent front distance emerged as the critical method parameters, the high-risk factors demanding experimental optimization. Moderate-risk items such as solvent and sample purity were flagged for stringent quality checks, while low-risk factors like sample preparation and detection wavelength were simply placed under routine control. This layered strategy, the authors note, is what separates a designed method from a lucky one.

To optimize the three critical parameters, the researchers turned to a Box-Behnken Design, a response surface methodology that explores quadratic effects and interactions among variables with remarkable economy. Where a traditional approach might demand dozens of experiments, the design required only seventeen runs, evaluated at low, medium, and high levels of each factor. Analysis of variance confirmed that quadratic polynomial models described both the retention factor and the peak area with high coefficients of determination, non-significant lack-of-fit tests, and strong predicted values, meaning the models could genuinely forecast chromatographic behavior rather than merely describe past experiments. Interaction terms proved largely insignificant, simplifying the final model without sacrificing predictive power. The exercise revealed a clear trade-off: longer solvent front distances produced larger peak areas but also broadened the bands and pushed the retention factor upward, eroding specificity.

The optimized conditions settled on a mobile phase of toluene, ethyl acetate, methanol, and formic acid in the ratio 10.5 to 3 to 1.5 to 0.45, a 20-minute chamber saturation, and a development distance of 60 millimeters. Under these conditions, desidustat produced a sharp, well-resolved band at a retention factor of 0.45 plus or minus 0.02, scanned densitometrically at 230 nanometers. The choice of a compact development distance, the authors explain, deliberately favored band quality over raw signal, a decision that reflects the design-space thinking at the core of AQbD: instead of chasing a single best response, the method balances resolution, sensitivity, and robustness simultaneously.

Validation followed the international ICH Q2(R2) guideline, and the numbers were impressive. The method showed excellent linearity across 600 to 1600 nanograms per band, with a correlation coefficient of 0.997. Accuracy, assessed by standard addition at three spiking levels, ranged from roughly 98.84 to 101.87 percent recovery, while precision, measured both within a single day and across days, stayed comfortably below the 2 percent relative standard deviation threshold. Sensitivity limits were established at 220.8 nanograms per band for detection and 517.9 nanograms per band for quantification, calculated by the instrument’s built-in signal-to-noise algorithm. Deliberate small perturbations in wavelength, saturation time, and development distance left the results essentially untouched, confirming robustness, and tablet excipients produced no interfering peaks.

Perhaps the most clinically revealing portion of the work is the forced degradation study, conducted under the spirit of ICH Q1A(R2). The researchers subjected desidustat to hydrolytic, oxidative, thermal, and photolytic stress. The drug proved most vulnerable to acidic hydrolysis, degrading by about 16 percent and yielding a distinct degradation product at a retention factor of 0.78, cleanly separated from the parent peak at 0.45. Under alkaline, oxidative, thermal, and sunlight exposure, degradation remained limited to 3 to 9 percent with no additional bands appearing, indicating the molecule is comparatively stable under those conditions. Because the method resolves the degradant without co-elution and passes peak purity checks, it qualifies as stability-indicating, meaning quality control laboratories can use it to verify not just how much drug is present, but whether the product has held up during storage. Structural identification of the degradation product by mass spectrometry was beyond the scope of the study, the authors acknowledge, but the chromatographic evidence of selective separation stands on its own.

The green credentials of the method were then put to a quantitative test using two widely respected assessment tools. The AGREE metric, which scores analytical procedures against the twelve principles of Green Analytical Chemistry on a scale from 0 to 1, awarded the method 0.87, comfortably within the excellent greenness category above 0.75. The ComplexGAPI tool, which renders the environmental impact of every step from sample preparation to final measurement as a color-coded pentagram, showed predominantly green and yellow zones with minimal red, the single red segment attributable to the toluene in the mobile phase. Even so, the overall environmental burden stays low because each plate requires only 10 to 12 milliliters of mobile phase while analyzing many samples at once, a fraction of the solvent consumed by conventional high-performance liquid chromatography, which typically depends on acetonitrile-rich systems and generates far more waste.

The comparison with earlier desidustat methods underscores why the work matters. Ultraviolet spectrophotometry offers simplicity but limited stability information; reversed-phase HPLC handles dissolution and assay work but at higher cost and solvent expense; liquid chromatography with tandem mass spectrometry delivers trace-level sensitivity for pharmacokinetics and doping control but is overkill and resource-intensive for routine tablet testing. The new HPTLC method occupies a pragmatic middle ground: sensitive enough for quality control, fast enough for high-throughput laboratories, cheap enough for routine deployment, and now formally documented as environmentally sustainable. The AQbD framework also eases method transfer between laboratories, a key regulatory requirement, because the statistically verified design space defines exactly how much the parameters can flex without compromising performance.

Beyond desidustat itself, the study offers a template. The authors argue that the same integration of risk assessment, designed experiments, and greenness evaluation can be extended to other pharmaceutical compounds, and they point toward future applications in impurity profiling and bioanalysis. Funded in part by a seed grant from Gujarat Technological University and published open access, the research arrives at a moment when the pharmaceutical industry is under growing pressure to shrink the environmental footprint of its laboratories. A method that quantifies a kidney-anemia drug with sub-microgram precision while using milliliters rather than liters of solvent may not make headlines the way a new molecule does, but it represents the quieter, cumulative kind of innovation that makes modern medicine both reliable and sustainable.

Subject of Research: Development of a green, stability-indicating HPTLC method using Analytical Quality by Design for quantifying desidustat in pharmaceutical formulations

Article Title: Integration of analytical quality by design and green chemistry principles in the development of an HPTLC method for Desidustat estimation

Article References: Bharvi, P., Thummar, B., Dudhatra, B., Joshi, H., Maheriya, B., Vadalia, J., & Thummar, K. (2026). Integration of analytical quality by design and green chemistry principles in the development of an HPTLC method for Desidustat estimation. Discover Green Chemistry, 1(1), Article 7. https://doi.org/10.1007/s44509-026-00007-1

Image Credits: AI Generated

DOI: 10.1007/s44509-026-00007-1

Keywords: desidustat, HPTLC, Analytical Quality by Design, green analytical chemistry, Box-Behnken design, stability-indicating method, chronic kidney disease anemia, ICH Q2(R2), AGREE metric, ComplexGAPI, pharmaceutical quality control, forced degradation