Sunscreen is one of the few categories where the marketing claim and the test result are the same number. A label that says SPF 50 has to be supported by a measured value, produced on a specific formula, tested under a defined method. That makes sunscreen development slower and more expensive than most skincare projects, and it makes the choice of manufacturing partner far more consequential. This guide covers the decisions a brand owner faces from brief to launch.

Filter selection and regional limits

The first constraint is not performance but geography. The list of permitted UV filters, and the maximum concentration of each, differs between the EU, the US, Australia, Japan and China. A formula built for one market may not be saleable in another without reformulation.

The US position is the tightest for new entrants: the organic filters widely used in Europe and Asia are not automatically available, which pushes many brands toward zinc oxide and titanium dioxide systems. The EU maintains a positive list with concentration limits and requires specific labelling for nano forms. China has its own registration pathway for sunscreens, with testing and filing requirements that affect launch timing.

Map the target markets before the first sample is made. Reformulating after clinical testing is the single most expensive mistake in this category. It is also worth confirming whether the product will be positioned as cosmetic or as an over-the-counter drug, because that classification changes the facility and documentation requirements.

Emulsion design and film formation

SPF is a measure of how much UV reaches the skin, so the film matters as much as the filter load. An even, coherent film blocks more than a patchy one at the same concentration. That is why two formulas with identical filter levels can test several points apart.

Emollient choice affects spreading and water resistance. Film formers improve rub resistance but can feel tight. Powder phases control shine but may settle during storage. Build the film first and tune the filter load second, otherwise you end up adding filters to compensate for a poor film and losing the sensory brief.

For daily-wear products, texture carries more weight than water resistance. A light fluid that people are willing to reapply beats a heavy cream with a higher lab number. For beach and sport products, the balance flips.

SPF, UVA and water resistance testing

In vivo SPF is measured on human volunteers using a defined light source and reading, and it is the reference method in most markets. In vitro approaches are useful for screening and for UVA protection factors, but they do not replace the in vivo number where regulators require it.

UVA protection is expressed differently by region: PA grades in Asia, a UVA protection factor and critical wavelength in the EU, and a broad spectrum test in the US. Commission the test panel that matches the market you are entering, and check that the laboratory is accredited for that specific method.

Water resistance claims need their own protocol, with immersion cycles followed by SPF measurement. Budget for repeat testing: the first submitted formula often fails by a small margin, and the fix usually means a formula change and a new panel.

Stability and packaging compatibility

Sunscreen actives are reactive. Avobenzone degrades in light, some organic filters interact with metal ions, and zinc oxide can catalyse degradation of other components. Stability testing must include light exposure, not only elevated temperature.

Packaging is part of the formula here. A clear bottle with a thin wall offers little protection, and a pump that draws air can oxidise the product between uses. Run compatibility testing in the final pack, at the fill volume you will actually sell, and include the label adhesive in the review.

Crystallisation is a common failure mode in high-filter systems, appearing as graininess or a white ring at the shoulder. It often shows up only after weeks at low temperature, so a short cycle is not enough.

Claims and launch documentation

Label text should stay within what the test supports. SPF, PA or broad spectrum, water resistance and "reef friendly" style statements each carry their own evidence expectations, and the last one is regulated differently by market.

The document pack for launch typically includes the formula, filter concentrations, test reports, stability data, packaging compatibility, safety assessment and, where required, registration certificates. Keep the tested formula and the production formula identical, and route any change through a formal assessment before it reaches the line.

Lead times in this category run longer than for ordinary skincare because testing sits on the critical path. Start the regulatory review and the test booking in parallel with sampling. Our product range includes sun care formats, the workshop page describes our filling capability, and project enquiries can go through the inquiry form. For company background, see about us.

Treat the SPF number as the last step of development, not the first. Get the film, the texture and the pack right, then measure what you have built.