Cosmetics formula and packaging compatibility trials
Commission trials using the final formula and production-intent packaging, with every contact material identified. Agree conditions, checks and acceptance criteria before testing, then submit traceable results to your Responsible Person and safety assessor before approving the combination. Cambridge China Bridge can coordinate factory samples and records.
Commission a defined formula and pack combination
Our beauty sourcing guide covers the wider launch process. For compatibility trials, issue a written brief identifying the formula revision, fragrance variant, intended shelf life, pack drawing and filling process. Test filled, assembled packs representative of production. An empty bottle test or a report for a similar cream does not establish compatibility for your combination.
Ask the laboratory and safety assessor to agree storage conditions, exposure duration, inspection intervals, sample quantities and acceptance criteria before samples are dispatched. Include foreseeable transport, storage and use conditions, such as light exposure, different pack orientations and repeated dispensing where relevant. Record what accelerated work can support and what needs continuing observation under normal storage.
Identify every contact material and control changes
Obtain a contact-material schedule covering the bottle or jar, internal coating, closure liner, seal, pump pathway, dip tube, dropper and elastomer parts. Include components exposed when the pack is tilted or used. Record material grades, suppliers, colourants and relevant coatings or adhesives, with component revisions and batch identities. Ask for composition information to be shared confidentially with the assessor where necessary.
Make written change notification a purchasing condition. A different resin grade, seal compound, recycled content, colourant or component supplier should trigger a documented review, even if the pack looks unchanged. Use the material substitution guide for the approval workflow. Ask the assessor and laboratory which comparisons or repeat trials are needed before accepting the change.
Check changes against retained controls
Retain baseline filled packs and fresh formula references. Ask the laboratory to select a suitable comparison container to help distinguish formula instability from pack interaction. At each agreed inspection, record appearance, fragrance, pack condition, leakage and dispensing performance using consistent methods. Standardise lighting for photographs and use defined sensory comparisons or analytical checks where the question warrants them.
| Observation | What to compare and investigate |
|---|---|
| Discolouration | Compare formula and pack separately with retained controls. Record staining, yellowing, fading or particles; investigate whether the formula, light exposure or a contact material is involved. |
| Swelling or softening | Compare seals, liners and elastomer parts before and after exposure. Check dimensions, deformation, tackiness, closure fit, leakage and pump operation. |
| Fragrance loss or change | Compare with the baseline and control container. Record reduced intensity and altered odour separately; investigate leakage, formula degradation or interaction with pack materials. |
| Apparently unchanged samples | Record the checks actually completed. Ask the assessor whether targeted chemical testing is needed; appearance and smell alone cannot resolve every compatibility question. |
Make the results traceable
Require a report that links each result to the formula revision, formula batch, component batches, assembly and filling details, sample identity and exposure history. Keep dated photographs, raw observations, measurement methods, deviations and failed results alongside the conclusion. Agree ownership and access to the underlying records when commissioning the work.
Use the laboratory sample chain-of-custody guide to record who selected, filled, sealed and dispatched the samples. Keep retained samples of the tested combination. If a failure occurs, pause approval, investigate the cause and document the corrective change before repeating the affected work.
Separate technical review from purchasing approval
Before making a cosmetic product available to consumers in Great Britain, its safety must be checked by a qualified safety assessor. Ask your Responsible Person to review the compatibility evidence with that assessor, including unexplained changes, missing material information and limits of the trial. Our Responsible Person guide covers appointment and responsibilities.
For purchasing approval, record the exact formula and pack revisions accepted, the report references, review comments, unresolved conditions and named approvers. Agree how relevant evidence will feed into the product information file and safety report. Release bulk production against that recorded combination, with continuing observations and change controls agreed. Cambridge China Bridge’s staff in China can coordinate samples and factory records for this review.
Frequently asked questions
Can I use the bottle supplier’s compatibility report?
Use it as background unless it covers your formula, contact materials and assembled pack. Ask the laboratory and assessor to identify the gaps before relying on it.
How long should cosmetics packaging trials run?
Agree duration with the laboratory and assessor against the intended shelf life, formula, pack and exposure conditions. Record the limits of accelerated results and arrange continuing normal-storage observations.
Does changing a pump seal need another trial?
Submit the new seal material and revision for review. Ask the assessor and laboratory whether focused comparisons or repeat trials are needed before approving the changed pack.
Does a compatibility pass replace a safety assessment?
No. Compatibility results provide evidence for review. Before a cosmetic product is made available to consumers in Great Britain, a qualified safety assessor must check its safety.