| 1 | Confirm Chemical Identity and Structural Fit | Chemical name, structure, CAS number where applicable, molecular formula, molecular weight, substitution pattern, stereochemical status, and salt or solvate form. | The specification should clearly distinguish the target pyridine isomer from positional isomers, regioisomers, tautomers, salts, hydrates, and solvates. Molecular mass should match the declared form. | Structure file, certificate of analysis, NMR data, high-resolution mass or LC–MS data, and a stated form designation. | Prevents wrong-isomer use, incorrect stoichiometry, and rework during route development. |
| 2 | Set Purity and Impurity Expectations | Assay, related substances, residual starting materials, regioisomers, catalysts or metals, residual solvents, water content, and inorganic residue. | Use a validated or appropriately qualified chromatographic method. A common early-discovery screen may request assay around ≥98% by HPLC or another justified method; tighter limits should be defined for late-stage or regulated work. | Lot-specific chromatogram, analytical method summary, impurity table, residual-solvent results, water result by Karl Fischer where relevant, and elemental-impurity assessment when metal catalysts are used. | Reduces false biological results and avoids impurity carryover into subsequent synthetic steps. |
| 3 | Review Solid-State and Handling Properties | Physical state, color, particle size, hygroscopicity, melting range, bulk density, flow behavior, solubility, and light or oxygen sensitivity. | Confirm whether the material is a free base, salt, hydrate, or solvate. Define handling controls for powders that are hygroscopic, volatile, electrostatic, poorly flowing, or sensitive to light or air. | Safety data sheet, handling instructions, storage recommendation, appearance specification, solubility information, and solid-form characterization when relevant. | Supports accurate weighing, reproducible charging, safer transfer, and consistent reaction concentration. |
| 4 | Test Stability Before Committing to Volume | Stability in the original container, solution stability, temperature sensitivity, humidity response, light sensitivity, oxidation risk, and retest or expiry period. | Request real-time and, where appropriate, accelerated stability data. For solutions, evaluate the intended solvent and concentration. Define acceptance limits for assay, degradation products, appearance, and water content. | Stability protocol, time-point results, recommended storage temperature, container-closure description, and assigned retest or expiry period supported by data. | Prevents potency loss, unexpected degradation, and changes in reaction performance during campaign storage. |
| 5 | Compare Batch-to-Batch Consistency | Results from multiple independent lots, assay variation, impurity pattern, water content, particle characteristics, yield history, and packaging configuration. | Review at least three representative lots when planning scale-up. Check that the same analytical methods and specification limits were used for each lot; investigate unexplained shifts in impurity profiles. | Three-lot or multi-lot CoA comparison, batch records or summary data, trend charts, deviation history, and change-notification procedure. | Lowers the risk that a process developed with one lot fails when a later lot is introduced. |
| 6 | Check GMP Readiness and Documentation | Quality system, material traceability, controlled specifications, analytical method qualification, deviation and change control, audit readiness, and manufacturing-site status. | Match the quality level to the development stage. For regulated programs, confirm documented manufacturing controls, batch traceability, data-integrity practices, and a formal process for notifying customers of changes. | Current CoA, specification, SDS, quality agreement where required, audit questionnaire, traceability statement, change-control policy, and applicable GMP or quality-system certifications. | Reduces qualification delays and supports transfer into clinical or commercial supply chains. |
| 7 | Validate Supply Capacity and Scale-Up Path | Available pack sizes, minimum order quantity, development and production batch size, lead time, forecast requirements, raw-material continuity, dual sourcing, shipping conditions, and capacity reservation. | Obtain written capacity information for the required scale, such as gram, kilogram, or larger campaigns. Confirm standard lead time, expedited lead time, supply allocation rules, and the ability to reproduce the same specification at larger batch size. | Capacity statement, lead-time range, production-batch history, forecast and allocation process, packaging qualification, shipping stability data, and contingency plan. | Avoids scale-up interruptions, emergency substitutions, and late changes to the synthetic route. |