| Ingredient identity | Exact chemical name, CAS number, molecular formula, molecular weight, structural form, and product specification. | The specification must clearly distinguish L-carnitine, L-carnitine L-tartrate, and acetyl-L-carnitine hydrochloride. These are different substances and must not be treated as interchangeable. | The ingredient name on purchasing, manufacturing, labeling, and regulatory documents should be consistent. | High |
| Supplier legal identity | Legal registration certificate, manufacturing-site address, operating permits, quality contact, and authorized signatory details. | The legal entity named on the quotation, quality agreement, invoice, CoA, and audit records should be traceable to the actual manufacturing or authorized distribution site. | A trading address alone is insufficient for qualification. Verify the actual production site and supply-chain role. | High |
| GMP certification | Current certificate, scope, covered site, issue date, expiry date, and most recent audit or inspection status. | The certificate should cover the relevant product category, such as food ingredients, dietary supplements, or pharmaceutical ingredients, and should be independently verifiable. | For U.S. dietary supplements, assess alignment with 21 CFR Part 111. For food uses, evaluate applicable food GMP and preventive-control requirements. | High |
| Quality-management system | Quality manual or questionnaire, deviation and CAPA procedures, change-control procedure, complaint handling, and recall procedure. | Documented procedures should cover batch release, out-of-specification investigations, traceability, retention samples, and supplier management. | Certification should support, not replace, a risk-based supplier audit and written quality agreement. | Medium–High |
| Batch-specific CoA | Certificate of Analysis showing batch number, manufacture date, retest or expiry date, test methods, results, specifications, and authorized approval. | The CoA must relate to the exact shipped lot. Results should be numerical where appropriate rather than only marked “pass.” | Compare the CoA against independent laboratory results during qualification and periodically thereafter. | High |
| Identity testing | Validated chromatographic or spectroscopic identity method, reference standard information, and representative chromatograms or spectra. | Identity should be confirmed using a scientifically appropriate method, such as HPLC, LC-MS, infrared spectroscopy, or a combination of methods. | Identity testing should detect substitution with a different carnitine form or an unrelated amino-acid derivative. | High |
| Assay and purity | Validated assay method, chromatographic conditions, system-suitability criteria, and impurity profile. | Use the buyer-approved specification for the selected form. A common commercial benchmark for high-purity powder is approximately 98.0%–102.0% on the applicable anhydrous or specified basis, but the contractual limit must be form-specific. | Do not compare assay results reported on different bases, such as as-is, dry basis, or anhydrous basis, without reconciliation. | High |
| Moisture and physical properties | Loss on drying or water-activity result, appearance, color, odor, solubility, particle-size distribution, and bulk density where relevant. | Set numerical limits based on the formulation and packaging. Typical purchasing specifications may include a moisture limit of not more than 2.0%–5.0%, but the correct value depends on the chemical form and process. | Moisture control is important because powder flow, caking, stability, and microbiological risk can change during transport and storage. | Medium–High |
| Elemental impurities | ICP-MS or ICP-OES results for lead, cadmium, arsenic, mercury, and any additional elements required by the risk assessment. | Limits must meet the destination-market requirements and the product’s intended use. Results should be reported in mg/kg or ppm with method detection limits. | Evaluate applicable limits under destination-market food, supplement, pharmaceutical, and contaminant regulations rather than relying on a generic “heavy metals pass” statement. | High |
| Residual solvents | Manufacturing-process disclosure and GC results for residual solvents, with the applicable analytical standard identified. | Results should comply with the applicable limits in ICH Q3C or the relevant food and pharmaceutical standard. “Not detected” should include the reporting limit. | Testing frequency should be justified by the actual process and solvent risk; a blanket annual statement may be inadequate for high-risk changes. | Medium–High |
| Microbiological quality | Total aerobic microbial count, total yeast and mold count, bile-tolerant Gram-negative bacteria where applicable, and specified pathogens. | At minimum, assess absence or controlled limits for Salmonella and Escherichia coli, with additional tests determined by intended use and jurisdiction. | Use recognized pharmacopoeial or validated food-microbiology methods and define sampling plans for each lot or risk category. | High |
| Allergen, GMO, and animal-origin status | Signed allergen statement, GMO statement, animal-origin statement, processing-aid declaration, and cross-contact control information. | Statements must cover the ingredient, processing aids, shared equipment, storage, and packaging materials where relevant. | Labeling requirements differ by market. Confirm whether the final product requires vegetarian, vegan, halal, kosher, or other status claims. | Medium–High |
| Stability and shelf life | Real-time or accelerated stability data, recommended storage conditions, retest period, packaging configuration, and transport study where available. | Shelf life should be supported by data for the specified packaging and storage conditions, not only by an unsupported fixed period. | Specify temperature, humidity, light exposure, resealing requirements, and minimum remaining shelf life at delivery. | Medium–High |
| Packaging and tamper control | Packaging specification, food-contact declaration where applicable, liner information, seal-control procedure, palletization details, and photographs of lot marking. | Each container should be sealed, clearly labeled, free from visible damage, and marked with product name, batch number, net weight, manufacture date, and expiry or retest date. | Packaging must protect the hygroscopic powder from moisture, contamination, and mix-ups during international transport. | Medium |
| Traceability and recall readiness | One-step-back and one-step-forward traceability records, mock-recall results, batch genealogy, and retention-sample policy. | The supplier should be able to identify raw-material sources, production records, shipped customers, and affected quantities for a specific lot. | Include notification timelines, recall responsibilities, and record-retention periods in the quality agreement. | High |
| Independent laboratory verification | Third-party test report, laboratory accreditation scope, sample chain of custody, method references, and original chromatograms where necessary. | Use a laboratory competent for the relevant methods; ISO/IEC 17025 accreditation for the specific test scope is a strong qualification criterion. | Test the first commercial lot, then use a documented periodic or risk-based verification program. Do not rely exclusively on supplier-issued CoAs. | High |
| Regulatory status by market | Regulatory assessment for the intended country, ingredient-status statement, permitted-use information, safety documentation, and import requirements. | The assessment must match the intended use: food, dietary supplement, medical food, cosmetic, or pharmaceutical application. | For the United States, review applicable requirements including 21 CFR Part 111 and Part 117. For the European Union, review applicable food law, food-supplement rules, contaminant limits, labeling, and national provisions. | High |
| Claims and labeling control | Draft label, intended daily serving, claims substantiation, nutrition or supplement facts data, warning statements, and translation review. | Claims must be truthful, non-misleading, supported by appropriate evidence, and permitted in the target market. | Supplier documentation does not automatically authorize health, disease, performance, or therapeutic claims made by the finished-product marketer. | High |
| Change notification | Written change-control policy covering raw materials, process, site, test methods, specifications, packaging, and subcontractors. | Material changes should require advance written notice, impact assessment, regulatory review, and customer approval where contractually required. | A new manufacturing site or substantial process change may require requalification, new stability data, or renewed regulatory assessment. | High |
| Commercial and logistics controls | Incoterms, minimum order quantity, lead time, payment terms, insurance, export documents, temperature and humidity controls, and delivery records. | Commercial terms should identify responsibility for customs, damage, delays, rejected lots, demurrage, and nonconforming material. | Avoid accepting product with inadequate remaining shelf life or unclear transport conditions, even when the batch CoA meets specification. | Medium |
