Quick answer: native beta-cyclodextrin and Hydroxypropyl Cyclodextrin are not interchangeable in a clear serum. Unsubstituted β-CD has low water solubility. The hydroxypropyl grade on this site lists water solubility above about 50 g/100 mL at 25°C. Ordering “cyclodextrin” without the hydroxypropyl INCI is not an order for HP-β-CD.
Placement and guest role are in Hydroxypropyl Cyclodextrin Carries Lipophilic Guests in Water. Dissolve and premix order is in Dissolve HP-β-CD First, Then Premix the Guest.
What each name actually is
Beta-cyclodextrin (unsubstituted) is a seven-glucose ring. Published solubility tables commonly put it near about 18 mg/mL in water at room temperature—a low single-digit g/100 mL ceiling. That shows up as slow dissolve, haze, or precipitation when formulators push clear aqueous systems or high guest loads.
Hydroxypropyl-β-cyclodextrin adds hydroxypropyl groups on the rim. That substitution disrupts the crystal packing that limits native β-CD and raises apparent aqueous solubility. Literature values for HPβCD often sit above about 600 mg/mL; Cosmetics Add’s grade targets >50 g/100 mL at 25°C with MS 0.40–1.50 and assay ≥98%. PubChem / CosIng-linked CAS lines for the hydroxypropyl material include 128446-35-5; the product page also lists 94035-02-6 for documentation matching.
Same “β-cyclodextrin cavity” shorthand does not make the lots the same purchase. Different INCI, different solubility, different COA fields (MS appears on HP grades; native β-CD does not carry that band).
Why clear serums usually pick the hydroxypropyl grade
A leave-on serum that must stay clear under water-heavy formulas is where the gap shows first. Native β-CD can still work in some emulsions or rinse-offs where a little haze is acceptable and cost dominates. It fails quietly when the brief assumed a transparent water phase and the warehouse shipped unsubstituted powder under a vague “cyclodextrin” PO.
Guest fit still matters. HP-β-CD does not dissolve every lipophilic molecule at every molar ratio just because the carrier itself is soluble. Judge clarity after complexation, not after the powder dissolves alone.
Alpha, gamma, and other substitutions are further forks
Alpha-cyclodextrin (six glucoses) and gamma-cyclodextrin (eight) change cavity diameter and guest preference. They are not silent substitutes for HP-β-CD. This site does not list them as the same SKU; if a brief names α or γ, open a separate identity check before sampling.
Methylated β-CD and sulfobutylether β-CD appear in pharmaceutical complexation literature as further modified rings. If the RFQ prints one of those names, do not fill it with Hydroxypropyl Cyclodextrin.
How to choose on the RFQ
| Brief needs | What to order |
|---|---|
| Clear serum / high water load / guest solubilization | Hydroxypropyl Cyclodextrin (this page) |
| Cost-sensitive emulsion where haze is tolerable and TDS allows | Native Beta-Cyclodextrin only after INCI is written |
| “Cyclodextrin” with no substitution named | Ask for INCI and MS (if HP) before sampling |
| α-CD, γ-CD, methylated, or SBE grades named | Match that INCI; do not ship HP-β-CD by default |
CIR and inventory reviews may discuss several cyclodextrins as cosmetic ingredients. That does not make them one warehouse code. Lock MS for HP-β-CD; lock assay and identity for native β-CD if that is truly the brief.
What to put in the quote or sample email
- Exact INCI: Hydroxypropyl Cyclodextrin vs Beta-Cyclodextrin (spell the substitution)
- For HP-β-CD: CAS line(s) you accept, MS band (for example 0.40–1.50), assay ≥98% if required
- Chassis type: clear serum, emulsion, or rinse-off
- Guest identity and whether clarity is mandatory
- Sample pack size, plus COA, SDS, and TDS
Documents for the hydroxypropyl grade are on the product page. Send the inquiry only after the INCI is locked in writing.
