# POLYMETHYLSILSESQUIOXANE (polymethylsilsesquioxane) — Global Cosmetic Regulatory & Formulation Monograph

- **Canonical URL**: https://www.inciname.com/en/ingredients/polymethylsilsesquioxane
- **Standard INCI**: `POLYMETHYLSILSESQUIOXANE`
- **KR MFDS Standard Name**: `폴리메틸실세스퀴옥세인`
- **CAS No.**: `68554-70-1`
- **EC / EINECS No.**: `N/A`
- **Origin**: `synthetic`
- **Functions**: 불투명화제
- **Molecular Formula / MW**: `—` (— g/mol)

## 1. 7-Track Official Regulatory Label Names
| Track | Official Label Nomenclature |
| :--- | :--- |
| KR (MFDS Standard) | 폴리메틸실세스퀴옥세인 |
| KR (Former Names) | 폴리메칠실세스퀴옥산, 폴리메틸실세스퀴옥산 |
| EU (CosIng 1223/2009) | POLYMETHYLSILSESQUIOXANE |
| US (PCPC / MoCRA INCI) | POLYMETHYLSILSESQUIOXANE |
| US (FDA OTC Monograph) | — |
| CN (NMPA IECIC) | 聚甲基倍半硅氧烷 |
| JP (JCIA / MHLW QD) | POLYMETHYLSILSESQUIOXANE  |

## 2. Layer 1 — Global 6-Region Statutory Summary
- **KR (MFDS)**: `none`
- **EU (1223/2009)**: `none`
- **US (FDA/MoCRA)**: `none`
- **CN (NMPA IECIC)**: `allowed` (Entry: `3962`)
- **JP (MHLW)**: `none`
- **ASEAN (ACD)**: `none`



## 3. Layer 2 — Toxicological & Historical Safe Use Concentrations
- Listed within general cosmetic GMP safety thresholds.

## 4. Layer 3 — Formulation Quartiles & Compatibility
- **Optimal pH Window**: 4 – 8
- **Max Process Temp**: ≤ 50°C
- **Synergy Pairings**: GLYCERIN, CAPRYLIC/CAPRIC TRIGLYCERIDE, TOCOPHEROL
- **Incompatibilities**: Verify phase compatibility under extreme pH or high electrolyte loads

## 5. Academic Monograph
■ [1. Chemical Identity & International Labeling Nomenclature]
  - INCI Name: POLYMETHYLSILSESQUIOXANE | CAS No.: 68554-70-1 | EC No.: N/A
  - Origin: SYNTHETIC | Functions: 
  - Physicochemical Profile: Formula      | MW /(Polymer/Complex) | /   | Ionic Nature: non-ionic | CosIng/MFDS 
  - Official Regional Label Names: US [POLYMETHYLSILSESQUIOXANE] · EU [POLYMETHYLSILSESQUIOXANE] · CN [聚甲基倍半硅氧烷] · JP [-] · JP Quasi-Drug [-]
■ [2. Dermatological Mechanism of Action & Functional Role]
  - Polymer formed by hydrolysis and condensation of methyltrimethoxysilane Classified under origin 'synthetic', it acts within the cosmetic vehicle or stratum corneum to deliver  performance and structural formulation stability.
■ [3. Global 6-Jurisdiction Regulatory Status & Safety Limits (Layer 1 & Layer 2)]
  - Regional Summary: KR: NONE | EU: NONE | US: NONE | CN: ALLOWED | JP: NONE | ASEAN: NONE (CN IECIC (2025) Entry No. 3962 (聚甲基倍半硅氧烷))
  - No specific Annex prohibition or numeric restriction across the 6 major jurisdictions (Permitted under general GMP safety assessment).
  - Official Safety & Historical Use Concentration (Layer 2): Quantum satis (QS) within standard cosmetic safety margins
■ [4. Formulation Dosage Guide by Product Category (Layer 3-A)]
  - [aqueous_serum] Typical range: 2.0 ~ 15.0% (Median 5.0%, Ref: Global Starter Formulation Library Statistical Distribution (n=19, GRANT 19)) — Aqueous serum, toner & hydrogel matrix formulation component
  - [emulsion_cream] Typical range: 2.0 ~ 10.0% (Median 4.0%, Ref: Global Starter Formulation Library Statistical Distribution (n=33, GRANT 33)) — Emulsion cream & lotion structural / conditioning agent
  - [sun_color] Typical range: 1.0 ~ 12.0% (Median 5.0%, Ref: Global Starter Formulation Library Statistical Distribution (n=47, GRANT 47)) — Sun care & color cosmetics dispersion / sensory modifier
■ [5. Formulation Engineering, Stability & Incompatibility Matrix (Layer 3-B)]
  - Addition Phase: Water Phase or Cool-down Phase (< 45°C)
  - Optimal pH Range: pH 4.0 ~ 8.0 | Max Process Temp: Max 50°C | Electrolyte Tolerance: MEDIUM
  - Incompatibility / Caution: Verify phase compatibility under extreme pH or high electrolyte loads
  - Synergy Pairings: GLYCERIN, CAPRYLIC/CAPRIC TRIGLYCERIDE, TOCOPHEROL | Reference Trade Names: POLYMETHYLSILSESQUIOXANE
■ [6. Peer-Reviewed Literature & Official Compendia Evidence]
  - PMID 25427646 (2014, Biofabrication): Novel preparation of controlled porosity particle/fibre loaded scaffolds using a hybrid micro-fluidic and electrohydrody

## 6. Linked PubMed Literature
- [PMID: 25427646] Novel preparation of controlled porosity particle/fibre loaded scaffolds using a hybrid micro-fluidic and electrohydrodynamic technique. — *Biofabrication* (2014)