1. Quality system and certifications
Look for a documented quality management system (ISO 9001:2015), a dedicated QA/QC structure, and a factory licence. Ask how deviations, change control and batch release are handled — mature answers signal a mature operation.
2. Analytical capability
A credible QC laboratory runs HPLC, GC, UV-Vis spectrophotometry, Karl Fischer, pH and TLC, with impurity profiling and stability studies. Without in-house analytics, a supplier cannot truly stand behind its specs.
3. Capacity and scale-up path
Confirm installed reactor capacity and the route from pilot/kilo lab to commercial batches. A clear scale-up path avoids surprises when your volumes grow. Ask about expansion plans so the partner can grow with you.
4. Documentation and regulatory support
CoA with every batch is the minimum. For regulated markets, ask about DMF support, MSDS/SDS and TDS, and willingness to host customer audits. Complete paperwork is what keeps your own filings on schedule.
5. Supply reliability
Evaluate raw-material sourcing security, lead times, and export experience. A manufacturer with established export logistics and regulatory documentation will ship reliably across borders.