| Chemical Identity | D-Chiro-inositol; molecular formula C6H12O6; relative molecular mass approximately 180.16 g/mol; CAS Registry Number 643-12-9. | Compare the sample with an authenticated reference standard using FTIR, Raman spectroscopy, or another validated identity method. | The sample spectrum must match the reference profile, with no unexplained major peaks. | Pass only after identity confirmation. |
| Chiral or Stereochemical Identity | The specification must clearly state that the material is the D-chiro stereoisomer rather than unspecified inositol or a mixed stereoisomer product. | Use a validated chiral chromatographic method, stereospecific optical-rotation test, or another scientifically justified method. | The test must distinguish D-chiro-inositol from other inositol stereoisomers and agree with the specification. | Reject if stereochemical identity is not demonstrated. |
| HPLC Purity | Lot-specific chromatogram, integration report, column information, mobile phase, detection conditions, and calculation basis. | Repeat testing at an independent laboratory using a validated HPLC or equivalent chromatographic method. | D-chiro-inositol purity must be ≥98.0% by HPLC, with the calculation basis clearly stated. | Pass when the independent result is ≥98.0%. |
| Assay or Content | Lot-specific assay result with units and basis, such as anhydrous basis or as-is basis. | Verify using a validated quantitative method, such as HPLC with suitable reference calibration. | The result must meet the agreed specification and the reported basis must be consistent with the purchasing specification. | Do not approve results without a stated basis. |
| Chromatographic Method Quality | Method validation or verification summary covering specificity, precision, accuracy, linearity, range, and system suitability. | Review the method against internationally recognized analytical-validation principles, including ICH Q2(R2) where applicable. | The method must be fit for purpose and able to resolve the main analyte from relevant impurities. | Pass only when method suitability is documented. |
| Water and Moisture | Water content or loss-on-drying result, storage conditions, and packaging information. | Test by Karl Fischer titration or another validated moisture method, depending on the material specification. | The result must remain within the agreed product specification and must not invalidate the assay basis. | Investigate any unexplained difference between lots. |
| Heavy Metals and Elemental Impurities | Results for relevant elemental impurities, reported in mg/kg or ppm, with the analytical technique identified. | Independent ICP-MS or ICP-OES testing with suitable blanks, calibration, and quality controls. | Results must comply with the applicable product specification and intended-use requirements. | Reject unexplained or out-of-specification results. |
| Microbiological Quality | Total aerobic microbial count, total yeast and mold count, and specified-pathogen results where required by the intended use. | Use an independent microbiology laboratory following recognized pharmacopeial or validated microbiological procedures. | All results must comply with the agreed specification for the intended application. | Acceptance depends on the final product category. |
| Residual Solvents | Manufacturing-process statement and residual-solvent test results, where solvents are used or reasonably possible. | Verify by headspace GC or another validated method suitable for the listed solvents. | Each detected solvent must comply with the applicable limits for the intended use. | Require a documented risk assessment if testing is not performed. |
| Pesticides and Contaminants | Risk-based statement covering pesticides, mycotoxins, allergens, and other contaminants relevant to the raw-material route. | Request independent LC-MS/MS or GC-MS/MS testing when the supply chain or source material creates a credible risk. | Results must meet the agreed contaminant limits or applicable legal requirements in the destination market. | Use enhanced testing for high-risk origins or processes. |
| Batch Traceability | Unique lot number, manufacturing date, retest or expiry date, quantity, country of manufacture, and packaging configuration. | Cross-check the lot number on the sample, container label, CoA, invoice, and shipping documents. | All records must describe the same lot and remain traceable from manufacture to delivery. | Reject mismatched or incomplete records. |
| Certificate of Analysis | Signed or electronically controlled CoA containing specifications, actual results, test methods, dates, and authorized approval. | Compare the CoA with independent laboratory results and verify that reported tests are lot-specific rather than typical values. | The CoA must show actual numerical results and a clear pass/fail conclusion for every critical attribute. | Do not rely on generic or undated CoAs. |
| Independent Laboratory Competence | Laboratory name, scope of accreditation, test method, report number, sample receipt date, and chain-of-custody information. | Check whether the laboratory is accredited to ISO/IEC 17025 for the relevant analytical activities, where available. | Critical results should be generated by a competent, impartial laboratory with documented quality controls. | Require justification for non-accredited testing. |
| Sampling Plan | Sampling quantity, number of containers sampled, sampling locations, sample identification, and storage conditions. | Review or conduct sampling using a documented, representative plan that prevents contamination and mix-ups. | The sample must be representative of the purchased lot and maintain full chain of custody. | Retest if sampling integrity is uncertain. |
| Packaging and Stability | Container material, tamper evidence, moisture protection, recommended storage temperature, and stability or retest information. | Inspect packaging and compare storage conditions with accelerated or real-time stability information when supplied. | Packaging must protect the material from moisture, contamination, and identification loss throughout transport. | Approve only with suitable transport controls. |
| Supplier Qualification | Manufacturing-site address, quality-system overview, change-control process, deviation handling, complaint procedure, and recall capability. | Conduct a risk-based document audit, remote audit, or on-site audit before long-term approval. | The supplier must demonstrate consistent lot control, documented quality procedures, and timely notification of significant changes. | Use provisional approval for the first lot if evidence is incomplete. |
| Final Release Rule | Completed qualification package containing identity, assay, ≥98.0% HPLC purity, safety testing, traceability, and independent laboratory evidence. | Perform a documented quality review before purchase release. | Approve only when all critical attributes pass and no unexplained discrepancy remains between supplier and independent results. | Approved for purchasing |