Span 80
[CAS# 1338-43-8]

Identification

• Classification: Surfactant >> Nonionic surfactant >> Polyol ester type
• Name: Span 80
• Synonyms: Sorbitan oleate; Sorbitan (Z)-mono-9-octadecenoate
• Molecular Formula: C₂₄H₄₄O₆
• Molecular Weight: 428.61
• CAS Registry Number: 1338-43-8 (9015-08-1)
• EC Number: 215-665-4
• SMILES: CCCCCCCC/C=CCCCCCCCC(=O)OC[C@H]([C@@H]1[C@@H]([C@H](CO1)O)O)O

Properties

• Density: 1.1±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.506, Calc.^*
• Boiling Point: 579.3±50.0 °C (760 mmHg), Calc.^*
• Flash Point: 186.2±23.6 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

Span 80, also known as Sorbitan monooleate, is a nonionic surfactant derived from the esterification of sorbitol and oleic acid. It appears as a yellow to amber-colored viscous liquid and is widely recognized for its emulsifying, dispersing, and stabilizing properties. As part of the sorbitan ester family, Span 80 is structurally characterized by its hydrophobic oleic acid tail and a hydrophilic sorbitan head group, which contribute to its amphiphilic nature. It has been extensively studied and documented in the field of surfactant chemistry, leading to its widespread application across various industries.

The discovery and development of Span 80 are closely linked to the advancement of nonionic surfactants in the early 20th century, particularly as scientists sought effective emulsifiers for oil-in-water and water-in-oil systems. With a hydrophilic-lipophilic balance (HLB) value of approximately 4.3, Span 80 is particularly effective as a water-in-oil emulsifier, meaning it helps stabilize water droplets within an oil phase. This property has made it a key ingredient in numerous industrial and commercial formulations.

One of the primary applications of Span 80 is in the food industry, where it is used as an emulsifier in various processed food products. It helps maintain the stability of margarine, spreads, and baked goods, preventing phase separation and improving texture. Its compatibility with other emulsifiers allows it to function synergistically in complex formulations, enhancing the consistency and shelf life of food products. Regulatory agencies have evaluated and approved its use in specific food applications, ensuring its safety within established limits.

In the pharmaceutical sector, Span 80 is widely utilized as an excipient in drug formulations, particularly in topical and transdermal delivery systems. Its emulsifying properties aid in the stabilization of active pharmaceutical ingredients in creams, lotions, and ointments. It is also employed in oral and parenteral drug delivery systems to enhance the solubility and bioavailability of poorly water-soluble drugs. Additionally, its role in controlled drug release formulations has been documented, where it influences the diffusion and release rates of active ingredients.

Span 80 is also extensively used in the cosmetic and personal care industry, where it contributes to the formulation of creams, lotions, and hair care products. It helps create stable emulsions, ensuring that water and oil components remain well mixed, thereby improving the overall texture and performance of cosmetic formulations. Its nonionic nature makes it compatible with a wide range of other surfactants, allowing for enhanced formulation flexibility.

In industrial applications, Span 80 is employed as a dispersant and emulsifier in coatings, paints, and lubricants. It aids in the uniform dispersion of pigments and enhances the stability of oil-based formulations. In agriculture, it is used in pesticide and herbicide formulations to improve the suspension and dispersion of active ingredients, ensuring better efficacy and application efficiency. Additionally, it is used in oil recovery processes, where it facilitates the emulsification of oil-water mixtures, enhancing the extraction and separation of hydrocarbons.

The safety and regulatory status of Span 80 have been extensively evaluated. It is considered to have low toxicity and is generally recognized as safe for use in food, pharmaceuticals, and personal care products within specified concentrations. Studies have indicated that it is biodegradable under standard environmental conditions, reducing concerns related to long-term environmental impact.

Span 80 remains an important surfactant in multiple industries due to its well-documented emulsifying, stabilizing, and dispersing properties. Its versatility, safety profile, and compatibility with other formulation ingredients ensure its continued use in food, pharmaceuticals, cosmetics, and industrial applications. The extensive body of research and regulatory approvals supporting its use further reinforce its role as a reliable and effective emulsifier in diverse formulations.

References

2024. Larvicidal Activity of Niosomal Formulations Loaded with Citrus limon (L.) Osbeck Essential Oil Against Vector Mosquitoes. BioNanoScience, 14(4).
DOI: 10.1007/s12668-024-01729-x

2024. Self-Nanoemulsifying/ Self-Assembled Cubic Nanoparticles Lyophilized Tablet: A Novel Biphasic Release Approach to Enhance the Bioavailability of a Lipophilic Drug. AAPS PharmSciTech, 25(7).
DOI: 10.1208/s12249-024-02952-1

2024. Development and optimization of a methimazole microemulsion for topical application: Formulation characteristics and transdermal permeation. Journal of Cosmetic Dermatology, 23(12).
DOI: 10.1111/jocd.16528