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Lactic acid AHA body lotion OEM/ODM manufacturing
Lactic Acid AHA Body Lotion · OEM/ODM
Lactic acid is often called “milk acid”, but the cosmetic raw material is made by fermenting carbohydrates or by chemical synthesis (PubChem), not extracted from milk. It is an alpha hydroxy acid (AHA), fully miscible with water, with a pKa of about 3.86; it loosens the surface layer of skin cells and helps hold moisture. Human evidence at home-use levels is modest and mostly from the 1990s: a 22-week double-blind trial in 74 women (three arms: 8% L-lactic acid cream, 8% glycolic acid cream, base cream) found less roughness and dullness on the forearms with the lactic acid cream compared with the base cream; a lotion containing L-lactic acid increased stratum corneum ceramides. A body lotion is spread over arms, legs and shoulders — sun-exposed areas — across a large skin area, which makes the two limits of ASEAN Annex III entry A6 all the more important: total AHA at most 10% calculated as the acids, final pH of at least 3.5, and a mandatory sunburn warning from 2.5% when the product contains no sunscreen. Every Butter-C AHA body lotion starts from three numbers — total AHA, pH, free acid — before skin feel. Butter-C offers full-service OEM/ODM manufacturing, from formula development to labeled finished product with its notification dossier.
Formula base
Lactic acid at the center, with emulsion and buffer arranged around pH
Unlike an AHA toner (an almost all-water solution), a body lotion is an emulsion with oils, emulsifiers and thickeners — every ingredient must withstand acidic pH for the whole shelf life.
Lactic acid — the named ingredient
INCI Lactic Acid. Butter-C's stocked raw material is a “Lactic Acid (and) Water” solution — the formula percentage is converted to pure acid using the certificate of analysis (COA). The L or DL form is specified: on human skin, a lotion with the L form increased stratum corneum ceramides by 48%, the DL form by 25%, and the D form not at all (Rawlings 1996, authors from an industry lab). Concentrated solution causes skin irritation and serious eye damage (GHS) — protective equipment and goggles when weighing.
Neutralization and lactate buffer
Sodium Hydroxide partly neutralizes the acid to reach the target pH; Sodium Lactate with Lactic Acid forms a buffer. Lactate salts still fall under entry A6 and count toward the total calculated as the acid — 1% anhydrous sodium lactate equals about 0.80% lactic acid. Neutralization lowers free acid, not the “total”.
An emulsion that tolerates acidic pH
Nonionic emulsifiers, fatty alcohols, light oils, silicone. Carbomer loses viscosity at low pH and with high lactate salt levels — Xanthan Gum or Hydroxyethylcellulose are used instead, with viscosity checked at the formula's actual pH.
Humectants, soothing agents, preservation
Glycerin helps reduce tightness; Panthenol and Allantoin are paired with a final pH of 4 or higher (formulation experience); sources disagree on the stable pH range of these two ingredients, so stability is confirmed by stability testing at the formula's actual pH. Sodium Benzoate (leave-on maximum 0.5% as benzoic acid) works at acidic pH and is paired with Phenoxyethanol; low pH does not replace a preservative system.
Key technical points
Four numbers and one warning to settle first
Two body lotions that both say “5% lactic acid” can act on skin very differently. The points below decide efficacy, gentleness and whether the notification dossier is valid.
Total AHA calculated as the acids
Annex III entry A6 covers “Glycolic and lactic acid, their common salts and simple esters”: skin products for general use “≤ 10% total when calculated as the acids”. The total includes lactic acid, glycolic acid (if any), the salt formed on neutralization and any added Sodium Lactate. Home-use studies used 5–12%; the 12% level (Smith 1996) already exceeds the ASEAN retail ceiling.
Final pH and free acid
Final pH must be “≥ pH 3.5”. With a pKa of about 3.86, the share of lactic acid in free form is estimated by the Henderson–Hasselbalch equation at about 70% at pH 3.5, about 42% at pH 4.0 and about 19% at pH 4.5 (calculated, not measured). Raising pH is gentler but exfoliates less; FDA notes that peeling depends on AHA type, concentration, pH and base, and that a cream base lets AHAs penetrate deeper than a plain solution.
A large area with many skin types
Body lotion also goes onto freshly shaved or waxed areas and thinner skin. From 1992 to February 2004, FDA received 114 reports of skin reactions to AHA products, most often burning (45), dermatitis or rash (35) and swelling (29); severe reactions were usually linked to strongly exfoliating products. Concentration and pH are settled through tolerance testing on the finished product, and the label advises avoiding abraded or freshly shaved skin.
Sun sensitivity and the warning statement
In an FDA-sponsored study, 10% glycolic acid (a representative AHA, not lactic acid) applied for 4 weeks increased UV-induced cell damage, which resolved one week after stopping (Kaidbey 2003). Footnote (13) of Annex III: “Labeling mandatory for products containing Glycolic and/or Lactic acids at a concentration ≥ 2.5% and do not contain a sunscreen. Not required for products that are intended to be applied to non sun exposed areas of the body…” A body lotion for arms and legs does not qualify for the “non sun exposed areas” exemption. Butter-C counts lactate salts (as the acid) toward the 2.5% threshold — a cautious reading, pending regulatory confirmation.
Three formulation directions
Three ways to put lactic acid into a body lotion
Lactic acid lotion with a lactate buffer
Partly neutralized lactic acid with Sodium Lactate to limit pH drift; entry A6 total no more than 10% as the acids, with the exact level set through tolerance testing — with reference to a 5% level (Smith 1996) and an 8% cream (Stiller 1996). For dry, rough skin on arms and legs already used to actives. The label carries the sunburn warning.
Lactic acid with urea for very dry skin
Following the 10% urea + 4% lactic acid formula tested on dry feet (Pham 2002 — people with diabetes, a medical context, results belong to the combination). Urea is more stable at pH 4–8, so final pH is set at 4 or above; urea increases penetration of other ingredients — tolerance is reassessed. Details on the urea body lotion page.
Low level, gentle positioning
Entry A6 total below 2.5% (counting salts as the acid — cautious reading): the footnote (13) warning is not mandatory, but the U.S. FDA still recommends a sunburn alert on AHA cosmetics — Butter-C suggests keeping sun protection advice. Reviewed sources have no human efficacy data at this level; claims stop at helping hold moisture and softening, to be tested on the finished product.
Packaging is designed with the formula
Pump or flip-top bottles in acid-resistant plastic; metal pump parts (springs) are immersion-tested with the sample in the stability study on the actual commercial packaging (formulation experience).
Parameters we monitor
What our R&D lab measures on every sample
These are the parameters Butter-C monitors while developing the formula and scaling it up to production. Specific limits are agreed with you on the approved sample and then written into the product's in-house specification.
- pH
- Measured at 25°C on every batch; the in-house pH range keeps a margin above the mandatory 3.5; pH drift tracked across stability checkpoints.
- AHA content
- Lactic acid (and glycolic acid if present) assayed by HPLC at the start and after stability testing; the entry A6 total calculated as the acids, including salts, is kept on file.
- Viscosity at acidic pH
- Rotational viscometer at 25°C; viscosity loss over time checked, since thickeners differ in acid and salt tolerance.
- Emulsion stability
- Centrifugation, freeze–thaw cycling, storage at 40°C; separation, color change and odor change monitored.
- Stinging & irritation
- Volunteer testing on arms and legs — the basis for setting concentration and pH before mass production.
- Microbiology & challenge test
- Tested at a GLP / ISO 17025-accredited laboratory; preservative efficacy (challenge) test per ISO 11930.
- Packaging compatibility
- Filled into the actual bottle and pump; deformation, packaging odor and signs of corrosion of metal parts monitored.
- Label check
- Total AHA, pH and the sunburn warning checked against Annex III entry A6 before the label artwork is approved.
Claims
Writing claims within cosmetic scope
Much of the lactic acid literature covers 30–92% peels performed by doctors, or a 12% ammonium lactate lotion that is a drug product in a medical context — marketing copy easily slides into that language. Conditions such as keratosis pilaris or ichthyosis need a dermatologist. Butter-C reviews label and marketing wording as soon as the notification dossier is prepared.
Gently exfoliates, helps the skin surface feel smoother
Instead of: peels skin, resurfaces skin, regenerates skin, “at-home body peel”.
Helps hold moisture, helps soften dry, rough areas
Instead of: claims about keratosis pilaris, folliculitis, ichthyosis or hyperkeratosis.
Helps skin look less dull
Supported by the 8% cream trial (less dullness on forearms compared with the base cream); a lotion needs testing on the finished product. Tyrosinase inhibition data are in vitro only. Instead of: whitens skin, body whitening, fades dark marks, removes melasma.
Contains X% lactic acid
State a percentage only if it is the total calculated as the acids and matches the assay; pH may be stated too. Instead of: percentages with unclear basis, figures above 10% on retail products.
Mandatory warning statement
Verbatim from Annex III: “Sunburn alert: This product contains an alpha hydroxy acid (AHA) that may increase your skin’s sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear sun protective clothing, and limit sun exposure while using this product and for a week afterwards.” The Vietnamese sub-label carries an equivalent translation approved by regulatory staff. Instead of: “does not cause sun sensitivity”, dropping the warning because the rest is “only salt”.
Directions and label cautions
Use in the evening, starting every other day; use sunscreen on exposed skin during the day and for a week after stopping; do not apply to abraded, freshly shaved, waxed or sunburned skin; use at a different time from products with retinol or BHA; stop use if redness or burning persists. Instead of: suitable for all skin types, safe during pregnancy, for children.
Manufacturing specifications
Our capabilities
- Texture
- Fluid lotion or light cream; an oil-in-water emulsion that tolerates acidic pH.
- Formats
- Pump bottle, flip-top bottle, tube in acid-resistant materials. Volume agreed when selecting packaging.
- Minimum order quantity
- Agreed per order — depends on the formula direction and chosen format.
- Testing
- Tested at a GLP / ISO 17025-accredited laboratory, with AHA assay and pH on every batch; a certificate of analysis is supplied with each batch.
- Documentation
- Product Information File (PIF) and cosmetic product notification dossier prepared by Butter-C, including the entry A6 total AHA calculation and irritation test results.
- Packaging
- Label design, printing and packing run in parallel with formula development; the sunburn warning is laid out from the first label draft.
Suggested product concept
Lactic acid body lotion with a lactate buffer for dry, rough skin
One product idea to help you picture the result — not a ready-made product for sale. The actual formula is developed around your brand's positioning and price range.
Lactic acid and Sodium Lactate, pH from 4
The named ingredient; entry A6 total no more than 10% as the acids, with the exact level set by stinging tests, with reference to the 5–8% levels tested in lotion and cream form.
Glycerin, Panthenol
Humectant and soothing pair alongside the acid; final pH is set at 4 or above, and Panthenol stability at that pH is confirmed by stability testing.
Thin, fragrance-free emulsion
Xanthan Gum thickener and light oils for a dry finish; fragrance-free, no added BHA or retinoids.
250 ml pump bottle
Acid-resistant plastic; the label carries the sunburn warning, evening-use directions and daytime sunscreen advice for exposed skin.
Customization options
What you can specify
The same product type can target very different customers. Tell us your requirements under the headings below, and our pharmacists will develop a matching formula.
AHA level
Below 2.5% (gentle positioning) or from 2.5% to 10% with the warning; retail products never exceed 10% total calculated as the acids.
pH and stinging
The closer pH is to 3.5, the more free acid and the more likely stinging; raising pH is gentler but reduces the effect.
Combinations
Urea, Glycerin, Panthenol, shea butter; Glycolic Acid, if added, shares the 10% ceiling.
Texture
A fast-absorbing fluid lotion or a light cream for dry seasons.
Fragrance
Fragrance-free recommended for a leave-on acid product used over a large skin area.
Ingredient direction
Paraben-free, mineral-oil-free, silicone-free, vegan — please state at the outset.
Further reading
Related topics
Lactic acid in cosmetics
Mechanism, evidence, the ASEAN 10% and pH 3.5 limits, sun sensitivity (in Vietnamese).
Sodium lactate in cosmetics
Lactate buffers, conversion to acid and free-acid share by pH (in Vietnamese).
UVA, UVB, visible light and the skin
Why AHA users need sun protection during and after use (in Vietnamese).
AHA glycolic acid toner manufacturing
Same entry A6, in toner form for the face.
Body exfoliator manufacturing
General page: granules, gels and acid products for body skin.
Urea body lotion manufacturing
The urea direction for very dry skin and keeping urea stable.
Body lotion manufacturing
General page: moisturizing, brightening, dry skin.
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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