Abstract
<title>Abstract</title> <p>The present study demonstrates the effectiveness of a systematic design-of-experiments approach in ensuring the robustness and reliability of analytical methods for routine quality control of high-potency cyclin-dependent kinase inhibitors (Jani & Vekariya, 2025). The validated method fulfilled all International Council for Harmonisation (ICH) regulatory requirements for accuracy, precision, linearity, and robustness (Khan et al., 2025), confirming its suitability for quantifying the active ingredient in the presence of stress-induced degradation products (Kharate et al., 2022). Analysis of variance and perturbation plots indicated that mobile phase components significantly affect the analyte’s retention behavior (Bagada et al., 2024). Validation data further demonstrated high specificity, with the method effectively separating the analyte from process-related impurities and degradation markers (Rao et al., 2025). Response surface methodology accurately defined the design space, ensuring that variations in critical method parameters do not compromise assay performance (Kashid et al., 2026; Majumder et al., 2025). Collectively, these results highlight the advantages of Analytical Quality by Design (AQbD) compared to conventional trial-and-error strategies (Deshpande et al., 2023; Palandurkar et al., 2022). The integration of chemometric tools also reduces solvent consumption and analytical time, supporting the principles of green analytical chemistry (Bharvi et al., 2026; Prajapati et al., 2022). This framework signifies a transition toward risk-based analytical procedures that promote consistent quality and global regulatory harmonization (Singh et al., 2024). Future investigations may extend these methodologies to complex drug-excipient matrices or bioanalytical applications involving heterogeneous biological samples (Lee et al., 2025). Adoption of this proactive methodology enables analysts to develop a predictive understanding of chromatographic responses, thereby enhancing the long-term reliability and adaptability of stability-indicating assays (Aggarapu et al., 2025; KRISHNARAJU & VELRAJ, 2025). Stress-induced samples showed distinct degradation constituents with retention factor values of 0.44 ± 0.05, 0.46 ± 0.05, 0.70 ± 0.05, 0.75 ± 0.05, and 0.38 ± 0.05. The analytical method demonstrated strong linearity across 100–600 ng per band, with a correlation coefficient of at least 0.999, confirming a proportional relationship between analyte concentration and chromatographic response. Precision studies produced percent relative standard deviation (RSD) values of 2.0% or less for both repeatability and intermediate precision, indicating consistent results. Accuracy, assessed by the standard-addition method, yielded a mean recovery of 99.59%, meeting regulatory acceptance criteria. Forced degradation experiments were carried out in compliance with the recommendations outlined by the International Council for Harmonization (ICH). The drug substance exhibited substantial susceptibility to degradation when exposed to acidic and oxidative environments, while demonstrating negligible decomposition under thermal and neutral hydrolytic conditions. These outcomes substantiate the capability of the developed AQbD-based HPTLC analytical approach to distinctly detect the parent compound from its degradation products. Furthermore, the method fulfilled the criteria for selectivity, precision, accuracy, and stability-indicating performance, endorsing its applicability for routine quality evaluation and stability monitoring of PBC within pharmaceutical dosage forms.</p>