| Product identity | Calcium alpha-ketoglutarate, also known as calcium 2-oxoglutarate; the exact salt form and hydrate status must be stated. | Compare the specification, product label, certificate of analysis, and an independent laboratory identity result. | Technical data sheet, certificate of analysis, product specification, and safety data sheet. |
| Assay and purity | Use a contract-specific assay limit. A common commercial purchasing target is not less than 98% assay, but the analytical method and reporting basis must be defined. | Validated HPLC or another suitable validated quantitative method, with reference standards and system-suitability records. | Batch-specific assay result, test method, chromatogram when required, and laboratory approval status. |
| Calcium content | Set a defined calcium range based on the declared chemical form and stoichiometry; do not compare results from anhydrous and hydrated materials without adjustment. | ICP-OES, ICP-MS, or another validated elemental-analysis method. | Elemental assay report and calculation basis, including dry basis or as-is basis. |
| Appearance and physical form | Uniform white to off-white powder, free-flowing or conforming to the agreed granulation; no visible foreign matter, abnormal odor, or excessive caking. | Visual inspection under controlled lighting and comparison with an approved reference sample. | Appearance specification, approved sample record, and deviation report if applicable. |
| Particle-size profile | Define the required mesh or particle-size distribution according to blending, capsule filling, tablet compression, or beverage use. No universal particle-size limit applies to every application. | Laser diffraction or sieve analysis using a documented sample-preparation procedure. | Particle-size specification, test result, and sampling plan. |
| Moisture and loss on drying | Establish a moisture limit suitable for flowability and stability; many buyers specify a low-single-digit percentage, subject to product validation. | Karl Fischer titration for water or a validated loss-on-drying method, with the method clearly identified. | Moisture result, method, equipment calibration record, and trend data where available. |
| Microbiological quality | Specify total aerobic microbial count, total yeast and mold count, and absence or limits for relevant pathogens according to the intended market and product category. | Testing by recognized compendial or validated microbiological methods in a qualified laboratory. | Microbiology certificate, method references, laboratory qualification, and environmental-monitoring summary when applicable. |
| Heavy metals and elemental impurities | Control lead, arsenic, cadmium, and mercury according to applicable food, dietary-supplement, or pharmaceutical requirements in the destination market. | ICP-MS or ICP-OES with appropriate detection limits and contamination controls. | Elemental-impurity report, risk assessment for raw materials, and corrective-action records if limits are exceeded. |
| Residual solvents and process impurities | Residual-solvent limits must reflect the solvents used and the regulatory requirements of the intended application; products should not be declared solvent-free without supporting evidence. | Headspace GC or another validated method, supported by a process-based risk assessment. | Residual-solvent statement, process-risk assessment, and batch test results when required. |
| Manufacturing controls | Controlled weighing, reaction, drying, milling, sieving, blending, and metal-detection steps should be defined and operated under documented procedures. | Quality-system audit, batch-record review, equipment-calibration review, and change-control assessment. | Manufacturing flow chart, master batch record, SOP index, calibration records, and deviation/CAPA procedures. |
| Quality-system certification | Prefer facilities operating under applicable GMP principles and a certified food-safety system such as HACCP-based controls or ISO 22000, depending on the product category. | Confirm certificate scope, issuing body, validity dates, site address, and audit status. | Current certificates, audit summaries, inspection responses, and supplier-qualification questionnaire. |
| Primary packaging | Use clean, food-contact-compatible packaging selected for moisture protection, seal integrity, and compatibility with the powder. | Review packaging specifications, food-contact declarations, seal checks, and container-closure integrity controls. | Packaging material specification, certificate of conformity, liner details, and packaging-line inspection records. |
| Bulk pack formats | Common wholesale formats include sealed bags inside fiber, HDPE, or comparable rigid drums; exact net weight should be agreed according to handling and transport requirements. | Verify net weight, tare weight, liner count, tamper evidence, pallet configuration, and shipping marks. | Packing list, package specification, palletization diagram, and lot-traceability record. |
| Label and traceability | Each package should show product name, lot or batch number, net quantity, manufacturing date, retest or expiry date where applicable, storage conditions, and handling information. | Match the label against the certificate of analysis, batch record, purchase order, and shipping documents. | Approved artwork, label-control procedure, traceability test, and recall procedure. |
| Storage conditions | Store tightly sealed in a cool, dry, clean, well-ventilated area, protected from direct sunlight, heat, moisture, and incompatible materials. Follow the validated product specification. | Review warehouse temperature and humidity logs, stock-rotation controls, pest-control records, and quarantine procedures. | Storage instruction, stability protocol, warehouse-monitoring records, and transport-condition requirements. |
| Shelf life and stability | Shelf life must be supported by real-time or accelerated stability data in the proposed packaging. Do not accept a fixed shelf-life claim without documented validation. | Review stability-indicating tests for assay, moisture, appearance, microbial quality, and physical performance. | Stability summary, approved shelf life, retest policy, and ongoing-stability plan. |
| Sampling and release | The lot should remain under quarantine until quality-control review confirms conformity with the agreed specification. | Check written sampling plans, representative sampling practices, retained samples, and quality-release signatures. | Sampling SOP, batch-release record, retained-sample log, and certificate of analysis. |
| Transport and delivery | Use clean, dry, enclosed transport that protects the sealed powder from rain, condensation, excessive heat, contamination, and package damage. | Inspect shipping containers, moisture barriers, pallet wrapping, temperature exposure, and delivery-condition records. | Shipping specification, packing list, transport record, and damage or excursion report. |
| Commercial comparison | Compare total landed cost, minimum order quantity, lead time, batch consistency, documentation quality, packaging options, and payment terms—not price alone. | Use a weighted supplier scorecard and approve samples before placing a recurring bulk order. | Quotation, sample-evaluation report, supply agreement, quality agreement, and agreed change-notification terms. |
