Most buyers approach sunscreen contract manufacturing in China with a texture in mind and a bottle already picked. That order of decisions is backwards. The formulation format — oil-in-water lotion, water-in-oil cream, anhydrous stick, silicone-heavy primer — decides which filling head can handle the bulk, which pack it will survive in for two years, and whether a 2,000-unit minimum is a comfortable pilot or a batch too small to compound properly. Pick the pack first and you will spend the sampling rounds discovering why the pump stalls.
This article walks through the four sunscreen formats a Guangzhou plant is most likely to quote, what each one demands from the compounding room and the filling line, how the pack choice follows from the emulsion, and which questions separate a plant that runs a format from one that will subcontract it. Regulatory notes are kept to one principle: sun protection follows a different legal route in every destination market, and that route is your obligation as the brand owner, not something the factory supplies.
The four format families and what they are chemically
A sunscreen is a UV-filter delivery system. The filters — organic molecules such as octocrylene, homosalate or ethylhexyl salicylate, or inorganic particles such as titanium dioxide and zinc oxide — need a carrier that spreads them evenly, holds them there as a film, and keeps them stable in the pack. The carrier is the format.
| Format | Emulsion system | Where the filters sit | Typical bulk behaviour | Usual pack | Filling approach |
|---|---|---|---|---|---|
| Lotion | Oil-in-water (O/W) | Organic filters dissolved in the oil phase; inorganic dispersed | Pourable to medium viscosity, shear-thinning | Bottle with pump, tube | Piston or gear-pump filler, ambient |
| Cream | O/W (rich) or water-in-oil (W/O) | As above; W/O carries more oil-soluble filter | High viscosity, can be temperature-sensitive | Tube, jar, airless | Piston filler, sometimes warm fill |
| Stick | Anhydrous, wax-structured | Filters dissolved or dispersed in oil/wax matrix | Solid at ambient, poured hot | Stick barrel, compact | Hot pour, cool, retract |
| Primer | Anhydrous silicone gel or W/Si emulsion | Filters in silicone/oil phase; often with elastomer | Thick gel, slip-heavy, air-entraining | Airless, tube, pump bottle | Piston filler, slow fill, degassing |
Yadun Cosmetics in Renhe Town, Baiyun District, lists sunscreen lotions, creams and primers plus base makeup as its first product line, and fills tubes, bottles and jars in-house. That is a stated scope, not a specification. It does not tell you which emulsion systems the compounding room runs, whether stick pouring exists, or what the smallest kettle is — and the factory page says capacity figures and equipment lists are still being compiled. Those gaps become your first three questions later in this article.
Why O/W and W/O are not interchangeable
An O/W lotion is water on the outside. It feels light, rinses off the hands, takes water-soluble preservatives easily and fills at room temperature. A W/O cream is oil on the outside: it is the format most water-resistant sunscreens use, it tolerates a heavier filter load in the continuous phase, and it is temperamental — W/O emulsions can invert or split if the compounding room adds the water phase too fast or the homogeniser shears too hard. A plant that runs both will talk about emulsifier systems, phase-addition rates and cooling profiles without prompting. A plant that only runs O/W will describe your W/O brief as "a rich cream" and quietly convert it. Ask directly which system the quoted formula is, and have the answer put on the formula sheet as an emulsion-type field.
Inorganic filters change the compounding job
Titanium dioxide and zinc oxide are not dissolved; they are dispersed. Dispersion quality decides whether the finished product looks uniform or streaky on skin, and whether particles settle in the pump over a summer in a Texas warehouse. Plants that handle mineral sunscreens seriously use pre-dispersed filter pastes or a dedicated dispersion step with a high-shear head, then check the bulk under a microscope or with a grind gauge for agglomerates. If your supplier's answer to "how do you check dispersion" is "we mix it well", budget an extra sampling round.
How the emulsion dictates the filling line
Filling is where formats reveal themselves. Bulk that compounded perfectly can still be ruined at the filling head, and the failure modes are format-specific.
- Lotions run on standard piston or gear-pump fillers. The risk is aeration: a shear-thinning O/W lotion pumped too fast pulls air, the fill weight drops, and the first squeeze from the consumer's tube is foam. Watch for a plant that checks fill by weight, not by volume, and that sets a fill-speed limit per formula rather than running every product at line speed.
- W/O creams often need a warm fill. Cool bulk is too stiff to flow into the piston without cavitating; overheat it and the emulsion thins, then re-thickens in the pack with a different texture from the approved sample. The insider tell is a plant that records bulk temperature at the hopper on the batch record and holds it inside a stated band.
- Sticks are a different process entirely. The molten mass is poured into the barrel or a mould above its set point, then cooled in a controlled way. Cool too fast and the stick cracks or forms a sink hole in the centre; cool too slowly and the wax structure grows coarse and the stick drags. Stick pouring uses dedicated equipment and a cooling tunnel or racks — it is not something a tube line does on a slow day. Confirm it exists before you brief it.
- Primers carry silicone elastomers and cross-polymers that trap air. Filled at line speed they come out with visible bubbles in a clear airless pack. The standard fix is vacuum degassing of the bulk before filling and a slower stroke on the filler. Ask whether the plant degasses, and how.
Spray sunscreens — pressurised aerosols and bag-on-valve — belong in a separate category. They need pressurised filling, propellant handling and hazardous-goods storage, and the factory page for this plant lists tube, bottle and jar formats only. Treat aerosol as outside scope unless a supplier shows you the pressurised line.
For a broader picture of how bottle, tube and pump lines are set up in Chinese cosmetics plants, the CMH guide to cosmetic filling and packaging lines covers equipment classes and changeover; the format-specific points above sit on top of it.
Pack choice follows the format — and the filters
Sunscreen is harder on packaging than moisturiser is. Organic UV filters are, chemically, oily aromatic esters — good solvents. Left in the wrong plastic for eighteen months they can migrate into the wall, soften it, or pull additives out of it. Three details that experienced sunscreen buyers check and first-time buyers do not:
- Tube laminate matters. Aluminium-barrier laminate (ABL) tubes resist filter migration far better than plain polyethylene, at a higher component cost. For a high-organic-filter lotion in a plain PE tube, ask for compatibility data before you approve the pack.
- Pumps have a viscosity window. A lotion pump dispenses cleanly within a band the pump maker publishes; a rich W/O cream sits above it and dribbles or sucks air. Ask the plant which pump reference it has already run with a comparable viscosity, rather than asking whether "a pump will work".
- Airless is not automatically better. Airless packs protect against oxidation and dosing drift, but a stiff cream can stall the follower piston, and the residual left in the pack at end of life counts against your net-content claim. Test the actual formula in the actual airless component through the full pack.
Compatibility is not a one-week job. A pack-compatibility study runs the filled product through accelerated storage — typically elevated temperature and cycling — and checks weight loss, pack deformation, colour, odour and filter content at intervals. Where it sits in the wider testing programme is covered in the CMH article on stability testing and shelf life for Chinese cosmetics OEM orders. What matters here is the sequencing: you cannot sign off the pack until the format is fixed, and you cannot fix the format until you know which emulsion system the plant will compound.
Where a 2,000-unit MOQ lands for each format
A minimum order of 2,000 units is workable for a full-category plant, but "2,000 units" means very different amounts of bulk depending on the format and fill size, and bulk quantity is what the compounding room cares about.
| Format and fill | Bulk per 2,000 units (approx.) | Practical note |
|---|---|---|
| Lotion, 100 ml bottle | ~200 kg | Comfortable single batch on a mid-size kettle |
| Cream, 50 ml tube | ~100 kg | Small for a W/O batch; ask the minimum kettle charge |
| Stick, 20 g barrel | ~40 kg | Below the practical minimum for many hot-pour setups |
| Primer, 30 ml airless | ~60 kg | Small batch; degassing time may dominate |
The number to obtain is the minimum and maximum kettle charge per emulsion system. A plant's smallest kettle sets the true floor: if it cannot compound below 150 kg with proper homogeniser immersion, a 2,000-piece stick order is either made oversize (and you pay for bulk you do not receive) or is refused. Yadun's published minimum is 2,000 units with standard formulations sampling in three days, custom in seven, and production in 15–30 days after sample approval — but per-format batch limits are not published, so ask for them in writing before you commit an SKU to a stick or primer format at pilot volume.
One related point: the 3-day standard sampling figure will apply to house formulas that already exist. A custom W/O sunscreen with a new filter system is a development project, and seven days is the quoted custom sampling time, not a promise that the first sample will pass your criteria. Plan two or three rounds.
Regulatory route is set by your market, not by the factory
Every format above is a sunscreen, and sun protection is treated as a distinct product class in most destination markets. The factory page notes that buyers exporting sun protection should confirm the destination market's regulatory route early, and that sunscreen is regulated as an over-the-counter drug in the United States rather than as a cosmetic. That means the US pathway — permitted filters, labelling, testing and the registration obligations that go with a drug product — is the responsibility of the brand owner or importer. A Chinese plant can compound to a filter list you specify; it cannot hand you US market clearance, and any supplier who implies otherwise should be pressed for the document.
Practical consequences for format choice:
- Some filters common in Asian and European sunscreens are not on the permitted list in the US. A format built around them needs reformulation for that market, which resets sampling and testing.
- The UK and EU route treats sunscreen as a cosmetic with specific filter annex limits; other Asian markets have their own lists. If you sell in three markets, you may need two formulas.
- Efficacy figures — SPF, UVA ratio, water resistance — belong to your own substantiation dossier and third-party test reports. They are not a factory attribute and should not appear in a quote as one.
Decide the market list before you decide the format. It is cheaper than deciding it after the tubes are printed.
Common questions
Can one plant run all four formats?
Many full-category plants in Baiyun District can run O/W and W/O emulsions on the same compounding equipment; stick pouring and anhydrous silicone gels need additional setup that not every plant has. The honest answer for any specific supplier is "ask, and ask to see it". A plant that runs eight product lines is more likely to have the range, but the factory page for this one explicitly says equipment lists are still being compiled.
Which format is easiest for a first order?
An O/W lotion in a bottle with a pump, at a 100 ml or larger fill. It compounds at ambient temperature, fills on standard equipment, tolerates the widest set of pumps, and the bulk quantity at 2,000 units is a normal batch. Sticks and primers are the formats to introduce once the relationship and the pack-compatibility work exist.
Does "cream" always mean water-in-oil?
No. Many products labelled cream are rich O/W emulsions. The word on the label tells you nothing about the emulsion system; the formula sheet does. Ask for the emulsion type as an explicit field.
Why does the factory ask for my target market before quoting a sunscreen?
Because the permitted filter list, and therefore the formula, depends on it. A plant that asks this question early is showing you it has shipped sunscreen before; one that quotes a generic "SPF lotion" without asking is a warning sign.
What to ask the supplier next
Work through these before the first sample request, and keep the written answers with the quotation.
- Which emulsion systems do you compound in-house — O/W, W/O, anhydrous? Get the answer per format, not a general yes.
- What is the minimum and maximum kettle charge for each system? Convert your planned order into bulk kilograms and check it fits.
- Do you pour sticks on-site, and on what equipment? If the answer is a partner plant, ask for that plant's name and licence details.
- Do you fill pressurised or bag-on-valve sprays? If not listed, treat it as no.
- How do you check dispersion of inorganic filters? Grind gauge, microscope, or nothing.
- What fill temperature and speed limits will you record for my formula? Ask to see a batch record template.
- Which pump and tube references have you already run with a comparable viscosity? Component part numbers, not brand names.
- Will you run a pack-compatibility study in my chosen component, and over what schedule?
- Which destination-market filter lists have you formulated to before? Confirm the answer for your own market in writing; the regulatory route remains yours.
Yadun Cosmetics is a reasonable example of the plant profile these questions are aimed at: a Baiyun District contract manufacturer operating since 2009 with 100–500 staff, listing sunscreen lotions, creams and primers among eight product lines, filling tubes, bottles and jars in-house, with a published minimum of 2,000 units and sampling quoted at three days for standard formulations. The factory profile states the scope; the answers to the nine questions above tell you whether the scope covers your format.