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Moumoujus

HYDROXYPROPYL METHYLCELLULOSE PHTHALATE.

Questionable CAS 9050-31-1 / ORAL CARE

Hydroxypropyl Methylcellulose Phthalate (HPMCP) is a pH-sensitive polymer, predominantly utilized in pharmaceutical formulations for targeted drug delivery. While primarily an excipient, its film-forming properties could theoretically offer some utility in topical cosmetic applications, specifically noted for oral care.

Summary

Film-forming agent

Science

Mechanism of Action

This ingredient functions as a pH-sensitive film-former, designed to remain stable in acidic conditions and dissolve in neutral to alkaline environments. When applied to skin, its film-forming capacity could create a protective barrier.

Research

Clinical Evidence

Insufficient-data confidence
Effective range N/A
Optimal

N/A

Transparency

Dusting Analysis

Not commonly dusted

The Formula

Formulation

Solubility
Both
Optimal pH 5 – 5.5
0 7 14

Stability

HPMCP exhibits chemical and physical stability at ambient temperatures for 3–4 years and maintains stability for 2–3 months at 40°C and 75% relative humidity. It is also stable under UV light for up to 3 months at 25°C and 70% relative humidity. However, elevated moisture and temperature levels can lead to degradation, specifically the hydrolysis of carboxybenzoyl groups.

Conflicts

  • Strong oxidizing agents
  • Certain coating solvents, such as acetone:propan-2-ol or dichloromethane:propan-2-ol, which may induce film splitting
  • Titanium dioxide concentrations exceeding approximately 10% in coating solutions, potentially reducing film elasticity and resistance to gastric fluid
  • High moisture environments, leading to hydrolysis and the formation of phthalic acid

Safety

Safety Profile

CIR Status
Not reviewed
Sensitization risk Unknown

HPMCP is generally recognized as safe (GRAS) by the U.S. FDA and EMA for use as a pharmaceutical excipient in oral capsules and tablets. The United States Pharmacopeia (USP) imposes a limit of 0.1% for total phthalates within HPMCP due to potential health considerations regarding trace phthalates. While considered non-irritating and non-toxic in pharmaceutical contexts, there is no specific CIR or SCCS review available for its topical cosmetic use. Notably, the European Union has proactively prohibited certain phthalic esters in cosmetic products.

Your Skin

Skin Compatibility

No Normal
No Dry
No Oily
No Sensitive
Irritancy Unknown
Comedogenicity Unknown

Our Assessment

Verdict

Questionable

While recognized as safe for pharmaceutical oral use, the lack of dedicated topical cosmetic safety reviews and general concerns regarding trace phthalates make this ingredient questionable for precision skincare applications.

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