Background/Objectives: Quality by Design (QbD) has revolutionized pharmaceutical development by transitioning from reactive quality testing to proactive, science-driven methodologies. Rooted in ICH Q8–Q11 guidelines, QbD emphasizes defining Critical Quality Attributes (CQAs), establishing design spaces, and integrating risk management to enhance product robustness and regulatory flexibility. This review critically examines QbD’s theoretical frameworks, implementation workflows, and industrial applications, aiming to bridge academic research and commercial practices while addressing emerging challenges in biologics, advanced therapies, and personalized medicine. Methods: The review synthesizes regulatory guidelines, case studies, and multidisciplinary tools, including Design of Experiments (DoE), Failure Mode Effects Analysis (FMEA), Process Analytical Technology (PAT), and multivariate modeling. It evaluates QbD workflows—from Quality Target Product Profile (QTPP) definition to control strategies—and explores advanced technologies like AI-driven predictive modeling, digital twins, and continuous manufacturing. Results: QbD implementation reduces batch failures by 40%, optimizes dissolution profiles, and enhances process robustness through real-time monitoring (PAT) and adaptive control. However, technical barriers, such as nonlinear parameter interactions in complex systems, and regulatory disparities between agencies hinder broader adoption. Conclusions: QbD significantly advances pharmaceutical quality and efficiency, yet requires harmonized regulatory standards, lifecycle validation protocols, and cultural shifts toward interdisciplinary collaboration. Emerging trends, including AI-integrated design space exploration and 3D-printed personalized medicines, promise to address scalability and patient-centric needs. By fostering innovation and compliance, QbD remains pivotal in achieving sustainable, patient-focused drug development.

In this study, we successfully synthesized a Pd-doped SnO₂ (Pd-SnO₂) material with a flower-like hierarchical structure using the solvothermal method. The material’s structural proper-ties were characterized employing techniques such as XRD, XPS, FESEM and HRTEM. A gas sensor fabricated from the 2.0 mol% Pd-SnO₂ material demonstrated exceptional sensitivity (R_a/R_g = 106) to 100 ppm ethanolamine at an operating temperature of 150 °C, with rapid response/recovery times of 10 s and 12 s, respectively, along with excellent linearity, selectivity, and stability, and a detection limit down to 1 ppm. The superior gas-sensing performance is attributed to the distinctive flower-like hierarchical architecture of the Pd-SnO₂ and the lattice distortions introduced by Pd doping, which substantially boost the material’s sensing characteristics. Further analysis using density functional theory (DFT) has revealed that within the Pd-SnO₂ system, Sn exhibits strong affinities for O and N, leading to high adsorption energies for ethanolamine, thus enhancing the system’s selectivity and sensitivity to ethanolamine gas. This research introduces a novel approach for the efficient and rapid detection of ethanolamine gas.

C₂₂H₂₂N₄O₈Mn, monoclinic, P2₁/c (no. 14), a = 12.7620(10) Å, b = 14.980(2) Å, c = 13.2910(11) Å, β = 120.070(5)°, V = 2198.9(4) ų, Z = 4, R _gt (F) = 0.0594, wR _ref (F²) = 0.1345, T = 293(2) K.

C₂₀H₁₃NiN₃O₇; triclinic, P1̄ (no. 2), a = 8.329(7) Å, b = 8.726(8) Å, c = 13.300(12) Å, α = 85.948(14)°, β = 75.509(14)°, γ = 72.258(13)°, V = 891.3(13) ų, Z = 2, R _gt (F) = 0.0373, wR _ref (F ²) = 0.1007, T = 296(2) K.

In this study, Ag-functionalized porous ZnO nanocomposites were successfully synthesized via pyrolysis of Ag-loaded ZIF-8 precursors. The structural and surface properties of the materials were systematically characterized using XRD, XPS, FESEM, and HRTEM analyses. A gas sensor fabricated from the optimized 3.0 wt% Ag–ZnO sample exhibited a significantly enhanced response (Ra/Rg = 103) toward 100 ppm acetone at an operating temperature of 275 °C, which is approximately 2.51 times greater than that of pristine ZnO. The sensor also demonstrated rapid response/recovery times (6 s/7 s), excellent linearity over a wide concentration range (500 ppb–200 ppm), good selectivity against common interfering VOCs, and stable performance, with over 95% response retention after 30 days. The improved sensing performance is attributed to the hierarchical porous structure derived from ZIF-8 and the increased oxygen vacancy concentration and chemisorbed oxygen species induced by Ag loading, which collectively increase surface reaction activity. This work provides an effective strategy for constructing noble metal-modified porous ZnO materials for sensitive and reliable acetone detection.

C₂₇H₁₉NiN₃O₅, monoclinic, P2₁/c (no. 14), a = 11.082(1) Å, b = 10.480(1) Å, c = 22.719(2) Å, β = 117.76(4)°, V = 2334.9(9) ų, Z = 4, R_gt(F) = 0.0489, wR_ref(F ² ) = 0.1271, T = 293 K.