A nonionic water-insoluble surfactant used as cosurfactant in oral lipid-based formulation SEDDS and SMEDDS. Cosurfactant and solubilizer in topical dosage forms.

Names & synonyms

USP NF Name

Propylene Glycol Mono and Dicaprylate NF
[May also be labeled as Propylene Glycol Monocaprylate (type I) NF until December 1, 2026]

EP Name

/

UNII Code (FDA)

RT9P9S09QI

Preferred Substance Name (FDA)

PROPYLENE GLYCOL CAPRYLATE

Handbook of Pharmaceutical Excipients

Propylene glycol monocaprylate

Chemical description

Consists of propylene glycol esters of caprylic acid (C8), composed of mono- and diesters.

Key characteristics

Product form

Oily liquid

Viscosity (mPa.s)

20 (20°C)

HLB

6

Main functionalities

Solubilizer for poorly-soluble APIs and bioavailability enhancer. Co-surfactant in LFCS Type II (SEDDS) and Type III (SMEDDS) formulations.

Solubilizer and skin penetration enhancer. Co-surfactant for microemulsion in topical formulation.

Safety of use is inferred by precedence of use in approved pharmaceutical products.

Main formulation technologies

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