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Zinc citrate toothpaste OEM/ODM manufacturing
Zinc Citrate Toothpaste · OEM/ODM
Zinc is a trace element naturally present in plaque, saliva and tooth enamel, and it has long been added to toothpaste as a salt. Zinc citrate (INCI Zinc Citrate) is the salt of citric acid with three zinc ions on two citrate groups; in the anhydrous form, zinc makes up about 34.2% of its weight. Dental trials on zinc citrate are fairly numerous — calculus, plaque, breath — but most assess the whole formula, usually a fluoride toothpaste or a combination with other agents, many involve industry, and an independent randomized trial in Vietnam in 2026 found no additional effect. A zinc citrate toothpaste therefore claims at cosmetic level: cleans teeth, helps keep breath fresh, “contains zinc citrate”; data on plaque, calculus and gingival indices are discussed only in the ingredient section. What shapes the formula is the zinc calculation: ASEAN Annex III limits water-soluble zinc salts to 1% calculated as zinc, so the salt level must be converted according to the anhydrous or hydrated form on the certificate of analysis (COA) and added to every other zinc salt. Unlike our general toothpaste page (fluoride, abrasives) and our alcohol-free mouthwash page, this page goes into what is specific to zinc citrate: the zinc conversion table, where the regulation is unclear about solubility, interactions with thickening polymers, reading each study correctly and why zinc citrate does not replace fluoride. Butter-C offers full-service OEM/ODM manufacturing, from formula development and testing to labeled finished product and notification dossier.
Formula base
Zinc citrate dispersed in a toothpaste base
Zinc citrate is only slightly soluble, so it is mainly dispersed in the paste alongside abrasive, humectants, foaming agent, flavor and a challenge-tested preservative system.
Zinc citrate: read the material correctly
PubChem: anhydrous form C12H10O14Zn3, 574.3 g/mol, CAS 546-46-3; dihydrate 610.4 g/mol (CAS 5990-32-9), trihydrate 628.4 g/mol (CAS 178326-57-3) — many trials used the trihydrate. The CIR Expert Panel report describes zinc citrate (dihydrate) as “slightly soluble in water”, soluble in dilute mineral acids and alkali hydroxides (Scott et al., 2024). CosIng lists the functions ORAL CARE, ANTIPLAQUE and one in the antimicrobial group — a declared-function list, not a claim. Not to be confused with zinc oxide (insoluble), zinc PCA, zinc gluconate, citric acid or sodium citrate.
Material on file and COA
The zinc citrate Butter-C keeps on file is declared as INCI Zinc Citrate. The COA for each lot must state the form (anhydrous, dihydrate or trihydrate), zinc content and heavy metals — CIR recommends controlling heavy-metal impurities in zinc salts. Without the form on the COA, zinc cannot be converted.
Paste base and foaming agents
Hydrated silica as the abrasive; sorbitol and glycerin as humectants; the structuring polymer is chosen after testing with the zinc salt (see Key technical points). Sodium Lauryl Sulfate for rich foam; Cocamidopropyl Betaine for a moderate-foam, SLS-free version.
Flavor, taste and preservation
Mint flavor and menthol for a cool feel; xylitol and sodium saccharin for sugar-free sweetness. Sodium Benzoate in oral care products is limited to 1.7% as benzoic acid (ASEAN Annex VI, Ref 1); the preservative system is challenge-tested per ISO 11930. The version described on this page is fluoride-free.
Key technical points
Zinc conversion, Annex III, interactions in the base, evidence and safety
These are the points where a zinc citrate toothpaste differs from a standard toothpaste; each is settled with the material COA, a calculation sheet and tests on samples.
Converting zinc by salt form
Calculated from the PubChem formulas (Zn 65.4 g/mol; zinc share rounded up, salt amount rounded down — the safe direction): anhydrous about 34.2% zinc, 1% zinc corresponds to about 2.92% salt; dihydrate about 32.2% zinc, about 3.11% salt; trihydrate about 31.3% zinc, about 3.20% salt. Example: 2% anhydrous zinc citrate carries about 0.68% zinc. These are calculations; the actual content follows each lot's COA.
Annex III Ref 24 and where the text is unclear
ASEAN Annex III (version 2026-1), Ref 24: “Water-soluble zinc salts with the exception of zinc 4-hydroxy benzene sulphonate (entry 25) and zinc pyrithione (entry 101 and Annex VI, entry 8)”, listed names “Zinc acetate, zinc chloride, zinc gluconate, zinc glutamate(20)”, maximum “1% calculated as zinc”; footnote (20): “The types of salts is not be limited to those listed in this reference.” Zinc citrate is not named, and the text does not define “water-soluble”, while CIR describes zinc citrate as slightly soluble. Butter-C reads it cautiously: zinc citrate is counted under Ref 24, zinc from every zinc salt in the formula (zinc chloride, zinc gluconate, zinc PCA…) is totaled and kept at ≤ 1% zinc — this reading needs confirmation by regulatory review for the notification market. Zinc citrate is not named in Annexes II, VI or VII; Ref 24 carries no mandatory label warning.
Polymer interactions and stability
According to Butter-C's oral care formulation chapter, zinc salts can lower viscosity and precipitate with anionic polymers (such as cellulose gum, carbomer) at high concentrations → fix the order of addition for the salt and the time viscosity is measured, and track viscosity over time; zinc can also precipitate with phosphate and carbonate (background knowledge, no quantitative source). Because it is only slightly soluble, zinc citrate must be evenly dispersed and checked for settling and redispersion after temperature cycling. Measured by atomic absorption spectrophotometry in aqueous solution, sodium lauryl sulfate increased the amount of zinc dissolved from zinc citrate (Giertsen et al., 1989) — physicochemical solution data, not data on a paste.
Dental evidence — results belong to the whole formula
Segreto et al. (1991): double-blind, stratified random allocation, 964 completers, 3 months — the 0.5% zinc citrate toothpaste gave calculus scores 13.7% lower than a control toothpaste without it; the abstract does not describe the base. Sowinski et al. (1998, 75 completers, 12 weeks) and Williams et al. (1998, 99 completers, 6 months) used a 2% zinc citrate toothpaste with 0.76% sodium monofluorophosphate versus the fluoride-only toothpaste; the abstracts do not mention randomization; Williams also measured a gingival index — gum disease data, not a basis for claims. A meta-analysis of 6-month trials found “no evidence of efficacy” for triclosan products containing zinc citrate (Gunsolley, 2006). A randomized trial in Vietnam in 102 patients with fixed orthodontic appliances and plaque-induced gingivitis, using 2% zinc citrate trihydrate toothpaste for 4 weeks, found in longitudinal analyses no additional clinical or microbiological effect; the authors declared no conflicts of interest (Nguyen et al., 2026). Of the 17 human studies in Butter-C's ingredient dossier, 8 have authors employed by or funded by industry; for studies from 2003 or earlier, PubMed lists only the first author's affiliation, so an industry role cannot be ruled out.
Breath, taste and cavities
In 13 volunteers given a cysteine rinse to induce odor, zinc ion solutions at 0.1–1% reduced volatile sulfur compounds in a dose- and time-dependent way; 1% zinc tasted somewhat unpleasant, while 0.1% was found acceptable (Young et al., 2003 — a short-term model; the abstract does not name the zinc salt). We have no checked source on the taste of zinc citrate in toothpaste → sensory testing on samples. A review (author from industry) notes that in caries clinical trials, adding zinc to fluoride toothpastes did not affect their ability to reduce caries (Lynch, 2011) — zinc citrate does not replace fluoride.
Safety and zinc exposure
The CIR Expert Panel (2024) assessed 27 zinc salts including zinc citrate: safe in the present practices of use and concentration described “when formulated to be non-irritating”; a 2016 survey reported 0.28–2% zinc citrate in oral care products. Neat zinc citrate powder was considered an irritant in a reconstructed human corneal epithelium model → eye protection and dust control when weighing. SCCS (2018): toothpaste at 1% and mouthwash at 0.1% zinc may lead to 3.54 mg zinc/day in adults and children aged 6–17 (14–35% of the upper limit), and toothpaste at 1% to 1.0–2.0 mg/day in children aged 0.5–5 (10–29%) — considered safe per se, but dietary zinc in children may already be close to or above the upper limit, and any additional source, including cosmetics, may lead to exceeding it in children. A PubMed search (10/2026) for the ingredient dossier found no reports of contact allergy to zinc citrate.
Three formulation directions
Three lines of zinc citrate toothpaste
Zinc citrate – mint, silica base
Zinc citrate at the levels used in trials (0.5–2%), hydrated silica, SLS, mint flavor and menthol; an everyday line, total zinc calculated from the salt form on the COA.
Zinc citrate, moderate foam, SLS-free
Cocamidopropyl Betaine instead of SLS, gentle mint, xylitol; “SLS-free” can be stated as a composition description; mildness is assessed on the finished product.
Zinc citrate in a non-ionic polymer base
Hydroxyethylcellulose and thickening silica instead of anionic polymers to reduce the risk of viscosity loss with the zinc salt (formulation experience, confirmed by viscosity tracking); texture and extrusion set on samples.
Packaging is designed with the formula
Laminate or aluminum tube (compatibility-tested with the zinc salt), screw cap or flip-top cap; the carton states “contains zinc citrate” but does not cite percentages from other studies.
Parameters we monitor
What our R&D lab measures on every sample
Below are the parameters Butter-C monitors during formula development and scale-up. Specific limits are agreed with you on the approved sample and then written into the product's in-house specification.
- Incoming zinc citrate COA
- Every lot: salt form (anhydrous or hydrate), zinc content, heavy metals; zinc conversion redone when the lot or supplier changes.
- Total-zinc sheet
- Zinc from zinc citrate and every other zinc salt in the formula, checked against 1% calculated as zinc (Annex III Ref 24); kept in the PIF.
- Zinc assay on the finished product
- Zinc content measured at manufacture and after aging; compared with the calculation sheet.
- pH
- Measured on a diluted slurry by the prescribed method; tracked across stability time points because zinc solubility and the preservative system depend on pH.
- Viscosity, extrusion
- Viscosity tracked over time after adding the zinc salt; paste extrudes evenly, sits on the brush, no water separation, no running.
- Stability
- Freeze–thaw cycling, storage at 40°C; watching for settling, grittiness, water separation, dried tube tips, color or taste change.
- Taste & odor
- Brushing tests for aftertaste (no checked source on the taste of the zinc salt — assessed on samples), cooling and sweetness.
- Microbiology & preservative challenge
- Tested at a GLP / ISO 17025-accredited laboratory; preservative efficacy (challenge) test per ISO 11930.
- Packaging compatibility
- Monitoring aluminum tube corrosion, flavor absorption into the tube liner and cap leakage.
Claims
Claims for a zinc citrate toothpaste
For oral hygiene and care products, Appendix 03-MP of Circular 06/2011/TT-BYT (the ASEAN cosmetic claims guidelines) does not accept claims about preventing tooth abscess, gum disease, gingivitis, mouth ulcers, periodontitis, pus around the teeth, palatitis, misaligned teeth or oral infections, nor whitening tetracycline stains. Plaque, calculus and gingival index data from trials are results of the formulas tested and are not transferred as claims to another product. Butter-C reviews the wording on labels and promotional materials when preparing the notification dossier.
Contains zinc citrate
Instead of: “prevents tartar”, “prevents plaque” with percentages borrowed from other studies, claims to act on bacteria.
Helps keep breath fresh (for the whole product, with testing)
Instead of: drug-like claims about bad breath, “reduces odor by 30%” borrowed from another study.
Cleans teeth; helps remove plaque during brushing
Instead of: drug-like claims about gingivitis, bleeding gums or periodontal disease.
Cool mint flavor
Instead of: “soothes the gums”, drug-like claims about the oral mucosa.
Fluoride-free — a statement of composition only
Instead of: prevents cavities, “zinc replaces fluoride”, remineralizes, restores enamel.
Warnings and intended users
Spit out after brushing, rinse, do not swallow. Stop use if the lips, gums or oral mucosa sting, redden or swell; persistent symptoms call for a dentist. Children: not positioned for young children — children's lines follow our children's toothpaste page, because SCCS notes that total zinc in children may exceed the upper limit when diet is added. Pregnancy and breastfeeding: data on oral care products with zinc citrate are insufficient, ask a doctor. Instead of: “completely safe for children”, “non-irritating”, “safe for mothers-to-be”.
Manufacturing specifications
Available capabilities
- Texture
- White or striped paste on request; zinc citrate is only slightly soluble, so the base is opaque.
- Pack formats
- Laminate tube, aluminum tube, screw cap or flip-top cap. Fill weight agreed when selecting packaging.
- Minimum order quantity
- Agreed per order and per flavor.
- Testing
- Performed at a GLP / ISO 17025-accredited laboratory, including zinc assay; certificate of analysis delivered with every batch.
- Dossier
- Product Information File (PIF) and notification dossier prepared by Butter-C, with the zinc citrate COA and the total-zinc sheet.
- Packaging
- Label design, carton, printing and packing run in parallel with formula development.
Suggested product concept
Fluoride-free zinc citrate – mint toothpaste
A product direction to help you picture the idea, not a ready-made product for sale. The actual formula is developed to match your brand's positioning and price range.
Zinc citrate as the named ingredient
COA stating salt form and zinc content; level within the 0.5–2% range used in trials, total zinc below 1%.
Cool mint
Mint flavor and low-dose menthol, total menthol on one sheet as on our peppermint toothpaste page.
Silica base and xylitol
Hydrated silica for moderate cleaning, xylitol and sorbitol for a sugar-free sweet finish; thickening polymer chosen after viscosity testing with the zinc salt.
120 g tube and carton
The carton states “contains zinc citrate”, “helps keep breath fresh”, a stop-use-if-irritated warning and claims reviewed against Appendix 03-MP.
Customization options
Options you can specify
The same product type serves different customer groups for different brands. Tell us your requirements in the areas below and our pharmacists will develop the matching formula.
Fluoride
This page describes a fluoride-free version. Most zinc citrate trials used fluoride toothpastes; when needed, the formula moves to a fluoride toothpaste with the mandatory limits and warnings (sodium fluoride: Annex III Ref 31, up to 0.15% calculated as F, totaled across all fluorine compounds; see our toothpaste page); “helps prevent cavities” is used only when confirmed by regulatory review and is not attributed to zinc citrate.
Zinc citrate level
0.5% or 2% as used in trials, or another level to fit the positioning — total zinc is always calculated from the salt form on the COA.
Combined zinc salts
Any additional zinc salt is added to the same zinc sheet, total ≤ 1% calculated as zinc; each salt needs its own COA and monograph.
Flavor
Strong mint, gentle mint, mint – cinnamon (calculated against IFRA limits, see our cinnamon toothpaste page) — set together with the aftertaste of the zinc salt on samples.
Foaming agent
SLS for rich foam or Cocamidopropyl Betaine for moderate, SLS-free foam.
Product set
Toothpaste paired with a zinc mouthwash or breath spray: total zinc calculated separately for each product; for mouthwash, the SCCS exposure scenario uses 0.1% zinc.
Further reading
Related knowledge
Zinc citrate in toothpaste
Zinc conversion table, reading each study correctly, the ASEAN 1% zinc limit and claims (in Vietnamese).
Toothpaste OEM/ODM manufacturing
The general technical base, fluoride and mandatory warnings.
Alcohol-free mouthwash OEM/ODM manufacturing
Zinc salts in a solution: clarity, sediment, taste masking.
Breath spray OEM/ODM manufacturing
Zinc salts helping keep breath fresh in a spray format.
Daily oral care routine
Background on brushing, fluoride and care steps (in Vietnamese).
Circular 06/2011/TT-BYT
Appendix 03-MP: claims not accepted for oral care products (in Vietnamese).
How we work
From idea to finished batch
Eight steps and three milestones signed off by both sides: approved sample, notification number, finished batch. Step-by-step details (in Vietnamese) →
Get started
Tell us about the product you plan to launch
Send us your product direction and expected volume. Our team will get back to you during business hours (Vietnam time, GMT+7).
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