Views: 299 Author: ZHENYIBIO Publish Time: 2026-11-10 Origin: Site
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● Why Solubility and Particle Size Data Must Be Evaluated Together
● Compare Cosmetic Raw Material Suppliers Using the Same Ingredient Basis
● How to Evaluate Cosmetic Ingredient Solubility Data
>> Replace "Water-Soluble" With Defined Test Conditions
>> Separate Equilibrium Solubility From Short-Term Clarity
>> Test the Intended Formulation Environment
● How to Read Particle Size Distribution Data
>> Understand D10, D50, and D90
>> Use Distribution Width to Reveal Hidden Differences
● Match the Particle Size Measurement Method to the Material
>> Laser Diffraction for Powder and Suspension Comparisons
>> Dynamic Light Scattering for Suitable Submicron Dispersions
● A Practical Five-Step Supplier Qualification Workflow
>> Step 1: Define the Product Requirement
>> Step 2: Send One Technical Questionnaire
>> Step 3: Run a Matched Laboratory Comparison
>> Step 4: Evaluate Batch-to-Batch Consistency
>> Step 5: Confirm Performance at Pilot Scale
● Build a Risk-Based Cosmetic Raw Material Supplier Scorecard
● Connect Botanical Performance With Responsible Sourcing
● Turn Supplier Data Into a Formulation-Ready Decision
>> What data should cosmetic raw material suppliers provide first?
>> Does smaller particle size always mean better solubility?
>> Can I compare DLS results directly with laser diffraction results?
>> Is D50 enough to qualify a botanical powder?
>> How many batches should I test before approving a supplier?
>> Does a clear solution prove that an active is dissolved?
To compare cosmetic raw material suppliers on solubility and particle size data, start with the test conditions—not the smallest particle size or the most impressive "water-soluble" claim. Reliable comparisons require matching ingredient composition, solvent, concentration, temperature, preparation method, and measurement technique.
For brands, wholesalers, and manufacturers sourcing botanical actives, this approach separates useful technical evidence from attractive specifications. A powder that disperses quickly may not dissolve completely. Two ingredients with identical median particle sizes may contain very different amounts of coarse material.
At ZHENYIBIO TECHNOLOGY INC, our focus combines traditional botanical knowledge with modern biofermentation for cosmetic ingredient and OEM/ODM development. Our purchasing perspective is straightforward: choose data that explains how an ingredient behaves in your formula, rather than treating a specification sheet as proof of compatibility.
Solubility describes the saturation concentration of a substance in a specified solvent at a given temperature. Particle size describes the dimensions of particles present under a particular measurement procedure.
These properties answer different questions:
- Solubility: How much material can dissolve under defined conditions?
- Dissolution rate: How quickly does that dissolution occur?
- Dispersibility: How readily can particles distribute throughout a liquid?
- Particle size distribution: What sizes are present, and in what proportions?
Smaller particles can dissolve faster because they expose more surface area. However, reducing particle size does not automatically make a poorly soluble botanical active sufficiently soluble at the intended dosage.
My first supplier-screening question would therefore be: "Are you measuring dissolved active, dispersed solids, or the delivery system carrying the active?"
That distinction determines whether the supplier's evidence supports your formulation objective.
Before comparing laboratory results, establish whether the materials are genuinely equivalent.
Two products carrying similar botanical descriptions may differ in active concentration, extraction profile, carrier content, residual moisture, or fermentation-derived components.
Request the following information:
| Comparison factor | What to request | Why it matters |
|---|---|---|
| Ingredient identity | INCI name and botanical identification, where relevant | Establishes what is being compared |
| Composition | Active assay, carrier, solvent, and other constituents | Separates active performance from carrier effects |
| Reporting basis | As-supplied or dry-weight basis | Prevents misleading concentration comparisons |
| Physical form | Powder, liquid, suspension, or encapsulated preparation | Determines appropriate testing |
| Traceability | Batch number, manufacturing date, and report date | Connects evidence to supplied material |
For fermented botanical ingredients, also clarify whether the product is a purified molecule, a filtrate, or a complex mixture.
A pure-substance solubility method may provide useful principles, but its applicability should not be assumed for every multicomponent extract.
A meaningful solubility statement needs more than an adjective.
Ask each cosmetic raw material supplier to report:
- Solvent identity and composition.
- Ingredient loading and units.
- Temperature and pH.
- Mixing speed and duration.
- Equilibration time.
- Method used to separate undissolved material.
- Analytical method used to quantify dissolved active.
- Replicate results and variability.
The OECD water-solubility guideline defines solubility as a saturation concentration at a specified temperature. Its scope covers essentially pure, stable, nonvolatile substances—not every botanical mixture.
For complex extracts, ask which component was measured. A result based on total dissolved solids is not equivalent to a result based on a particular active marker.
A clear sample after mixing is encouraging, but it does not establish equilibrium solubility or long-term compatibility.
The preparation may contain colloids, micelles, or temporarily supersaturated material. Conversely, an extract may remain colored even when relevant constituents are dissolved.
A stronger comparison combines appearance with analytical measurement.
Ask suppliers whether the reported value represents:
1. A saturation measurement.
2. A timed dissolution test.
3. A visual compatibility observation.
4. An application test at the recommended dosage.
Each result can be useful. Problems arise when different endpoints are presented as interchangeable.
Water-only testing is a starting point, not a complete formulation decision.
Compare shortlisted materials in the intended solvent system and relevant pH range. Include formulation components that may affect performance, such as electrolytes, humectants, or surfactants.
For an aqueous serum, prioritize compatibility in the actual aqueous base. For an emulsion, clarify the addition phase, processing temperature, and behavior after cooling.
Define success before testing. "No visible precipitation at the target dosage under the agreed observation conditions" is more actionable than "good solubility."
For a volume-based distribution:
| Parameter | Meaning | Purchasing relevance |
|---|---|---|
| Dv10 | 10% of particle volume lies below this diameter | Describes the fine end |
| Dv50 | 50% lies below this diameter | Describes the median |
| Dv90 | 90% lies below this diameter | Helps characterize the coarse end |
D50 is not the largest particle size and does not describe the whole distribution.
A supplier reporting only "average particle size: 10 μm" leaves important questions unanswered. Ask whether that value is a mean or median, and whether the distribution is based on volume, number, or scattering intensity.
Also request the complete distribution curve. A single summary value can conceal multiple particle populations.
A common measure of distribution width is:
Span=(D90−D10)/D50
Consider this hypothetical comparison, using the same validated volume-based method:
| Supplier | D10 | D50 | D90 | Span |
|---|---|---|---|---|
| A | 3 μm | 10 μm | 22 μm | 1.9 |
| B | 1 μm | 10 μm | 55 μm | 5.4 |
Both suppliers report the same median. Supplier B has a broader distribution and a larger D90.
This does not automatically make Supplier A superior. It identifies a difference that should be tested against product requirements, such as texture, dispersion behavior, and process compatibility.
The figures illustrate interpretation only; they are not ZHENYIBIO test results.
Laser diffraction commonly reports volume-based particle size distributions.
To compare reports, request:
- Wet or dry measurement configuration.
- Dispersant composition.
- Optical model and refractive-index inputs.
- Sample concentration or instrument loading.
- Stirring, circulation, and sonication conditions.
- Repeat measurements and full distribution curves.
Preparation matters. Strong sonication may break agglomerates that remain intact during normal manufacturing. Insufficient dispersion may leave clusters that obscure the underlying particle population.
Neither preparation is automatically wrong. The method must measure the property relevant to your process.
Dynamic light scattering, or DLS, measures diffusion-related hydrodynamic size in liquid. Common outputs include the Z-average and polydispersity index.
The Z-average is not interchangeable with a laser-diffraction Dv50.
DLS results depend on sample preparation and inputs such as liquid viscosity and temperature. Larger particles can strongly influence scattering, making contamination and aggregation important concerns.
For encapsulated botanical actives, ask what the reported size represents: carrier droplets, vesicles, aggregates, or active-containing particles.
A small carrier size alone does not establish higher efficacy, better penetration, or adequate safety. Those claims require separate evidence.
Start with the finished product.
Document the dosage, solvent system, pH, processing conditions, appearance expectations, and relevant packaging constraints.
A clear serum and an opaque botanical cream should not automatically use identical acceptance criteria.
Give every supplier the same questions and reporting template.
Request batch-specific certificates of analysis, detailed methods, supporting reports, and an explanation of any missing data.
Distinguish a routine release specification from a one-time development study.
Test shortlisted samples under the same conditions.
For solubility-related work, use a justified analytical method and verify that sample separation does not unintentionally remove dissolved active or retain fine particles.
For particle sizing, confirm representative sampling and repeatable preparation.
Repeat measurements of one preparation do not replace independently prepared samples.
Where commercially feasible, compare three independent production batches as an initial screening exercise.
This is a proposed purchasing practice, not a universal qualification rule. The required sampling plan depends on ingredient risk and available manufacturing history.
Investigate changes in particle distribution, dissolved-marker concentration, moisture, and application behavior.
Repeat critical checks using realistic production equipment and order of addition.
Record mixing time, processing temperature, visible residue, and relevant observations after storage.
Laboratory success supports advancement; it does not replace finished-product stability, safety, or regulatory assessment.
A useful scorecard rewards relevant evidence rather than impressive terminology.
The following weights are an illustrative internal model, not an industry standard:
| Evaluation area | Suggested weight |
|---|---|
| Solubility evidence relevant to the formula | 30% |
| Particle size method and reporting quality | 25% |
| Batch consistency and traceability | 20% |
| Pilot-scale application performance | 15% |
| Technical responsiveness and change notification | 10% |
Score each area from zero to five, then apply the weighting.
Keep mandatory requirements outside the weighted total. An unresolved identity issue, missing essential safety documentation, or failed compatibility test should not be cancelled out by strong customer service.
Price comparisons should also use an equivalent basis: active content, usable dosage, processing requirements, and rejected material—not simply cost per kilogram.
Natural origin and biofermentation do not, by themselves, prove sustainability or superior performance.
Evaluate those claims separately from solubility and particle size.
Ask for evidence appropriate to the claim: botanical traceability, carrier composition, production inputs, and the defined boundaries of any environmental comparison.
For OEM/ODM projects, connect ingredient qualification with formulation responsibilities. Agree who sets specifications, approves substitutions, investigates deviations, and evaluates manufacturing changes.
This prevents a technically promising ingredient from becoming a poorly controlled commercial dependency.
The strongest cosmetic raw material suppliers explain both what their data demonstrates and where its limits lie.
At ZHENYIBIO TECHNOLOGY INC, we position botanical knowledge and modern biofermentation within that evidence-led approach to ingredient and OEM/ODM discussions.
Send our team your target ingredient, intended dosage, formulation type, pH range, and current compatibility challenge. Request a project-specific discussion covering available solubility evidence, particle size methods, sample evaluation, and qualification requirements.
The objective is not the smallest reported number. It is a reproducible ingredient specification that supports your product and manufacturing process.
Start with ingredient identity, composition, active assay, batch traceability, and relevant solubility or particle size reports. Each numerical result should include its method, units, and test conditions.
No. Smaller particles can increase dissolution rate, but they do not automatically provide sufficient equilibrium solubility. Evaluate the ingredient at its intended dosage in the relevant formulation environment.
Not as equivalent values. DLS commonly reports hydrodynamic Z-average size, while laser diffraction commonly reports volume-based distributions. Compare like-for-like methods or use complementary measurements with clearly explained interpretations.
Usually not. Request D10, D90, the distribution basis, the full curve, and preparation details. These reveal differences that a shared median can conceal.
There is no universal number. Three independent batches can provide an initial consistency screen, but qualification should reflect ingredient complexity, application risk, manufacturing history, and your quality requirements.
No. Visual clarity cannot reliably distinguish molecular dissolution from all colloidal or solubilized systems. Use an appropriate analytical procedure and a justified separation method where necessary.
1. OECD. *Test No. 105: Water Solubility*. OECD Guidelines for the Testing of Chemicals, Section 1. Published July 27, 1995. Defines saturation concentration, test scope, temperature control, and water-solubility methods. [oecd]
2. HORIBA. *Setting Particle Size Specifications*. Explains distribution bases, D10/D50/D90, span, and method-appropriate specifications. [horiba]
3. HORIBA. *Understanding and Interpreting Particle Size Distribution Calculations*. Explains volume-based laser diffraction results and particle size percentiles. [horiba]
4. HORIBA. *What Is the Z-Average Size Determined by DLS?* Explains cumulants analysis and why Z-average differs from a volume median. [horiba]
5. HORIBA. *Dynamic Light Scattering Particle Size Distribution Analysis*. Describes diffusion-based sizing, hydrodynamic interpretation, and required liquid properties. [horiba]
6. HORIBA. *Introduction to Laser Diffraction*. Covers optical models, refractive index, dispersant selection, sonication, and reproducibility. [static.horiba]
7. OECD. *Guidance on Sample Preparation and Dosimetry for Manufactured Nanomaterials, 2025 Edition*. Discusses sample preparation, dispersion characterization, and the distinction between primary particles and aggregates or agglomerates. Its scope concerns manufactured nanomaterials, not botanical ingredients generally. [oecd]
