
Self Emulsifying Drug Delivery Systems (SEDDS)
Self emulsifying (or self microemulsifying) drug delivery systems (SEDDS or SMEDDS) are mixtures of oils, surfactants, solvents, and drug substance that rapidly and spontaneously form oil-in-water emulsions or microemulsions when introduced into aqueous phases under gentle agitation.
Oral administration offers a non-invasive, cost-effective, and convenient administration route. However, as API’s become more complex, so does the delivery of these drugs. Issues like product stability, degradation upon ingestion, and drug uptake can hinder product efficacy, and can sometimes mean the difference between having to take one capsule versus multiple. As a formulations solution provider, we have responded to the challenges involved in the oral delivery of complex APIs with our Oral Lipid Delivery platform. With a wide breadth of ingredients to choose from, you can have the ability to improve the bioavailability of a poorly water soluble and difficult to deliver API via selecting the right ingredient or ingredients, or by formulating a self emulsifying or self microemulsifying drug delivery system (SEDDS or SMEDDS).

Product finder
View Our Super Refined™ portfolioWhat is a SEDDS or SMEDDS formulation?
Self emulsifying (or self microemulsifying) drug delivery systems are mixtures of oils, surfactants, solvents, and drug substance that rapidly and spontaneously fine oil-in-water emulsions or microemulsions when introduced into aqueous phases under gentle agitation. Upon emulsification, the lipophilic components disperse to form small lipid cores surrounding by surfactant in an aqueous continuous phase. Depending on the exact characteristics of the drug, it may be incorporated into the core, surfactant layer, of a combination of the two.
From the perspective of oral formulations, these mixtures are typically loaded into softgel capsules. Upon ingestion and digestion, the formulation readily disperses in the stomach and forms a stable emulsion or microemulsion with the drug evenly dispersed throughout via the small lipid cores. These, in turn, can get readily absorbed either through the gastric or hepatic pathways.
What are some of the benefits of using a SEDDS or SMEDDS formulation?
There are a number of benefits that come from the use of self emulsifying drug delivery systems, including:
- Improvement in oral bioavailability
- Ease of manufacture
- Reduction of inter/intra subject variability and food effects
- Ability to deliver a wide range of molecules, including peptides
- Decrease in the influence of lipid digestion effects on the drug
- Increase in drug loading capacity
What products are part of the Oral Lipid Delivery platform?
The list encompasses a wide variety of chemistries, from oils to various ester mixtures, ethoxylates to fatty acids, oil derivatives and more. A number of these ingredients are available as Super Refined™ products, which add an extra element of purity so as to ensure the stability and integrity of the drug and formulation throughout its shelf life.

Phase Diagrams
Phase diagrams are useful to determine the properties of multicomponent systems:
- Apexes represent single-components
- The perimeter represents two-component systems
- The body represents three-component systems
Phase behaviours of formulations can be characterised by investigating different ratios of the same excipients. Speak to one of our technical experts on the methodology, product support, and potential customer collaborations.
SEDDS and SMEDDS product portfolio
Croda offers a breadth of high purity ingredients that lend themselves well to solubilising a poorly water soluble drug, stabilising it once it’s in solution, and creating SEDDS and SMEDDS formulations. The list is constantly growing, and we strive to work with our customers to provide them with a solution they need!
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Crodamol™ EO pharma
Low viscosity solvent for lipophilic actives. Rapidly absorbed by body tissues. Dermal penetration enhancer. Required HLB value of 11. Recommended topical usage levels of 0.5-5%.

Super Refined™ Cottonseed
Cottonseed-derived triglyceride that has been Super Refined™ to remove impurities.
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Super Refined™ Olive Oil
Olive-derived triglyceride that has been Super Refined™ to remove impurities. Purified to yield a water-white, odourless, neutral non-polar lipid with a low peroxide value. Can be used topically as an...

Super Refined™ Sesame Oil
Sesame-derived triglyceride that has been Super Refined™ to remove impurities. Purified to yield a water-white, odourless, neutral non-polar lipid with a low peroxide value. Its major use is as a...
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Super Refined™ Soybean Oil
Soy-derived triglyceride that has been Super Refined™ to remove impurities. Purified to yield a water-white, odourless, neutral non-polar lipid with a low peroxide value. Used in pharmaceutical...
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Super Refined™ Peanut Oil
Peanut-derived triglyceride, that has been Super Refined™ to remove impurities. Purified to yield a water-white, odourless, neutral non-polar lipid with a low peroxide value. Used as an excipient in...
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Super Refined™ Castor Oil
Super Refined Castor Oil is a highly purified version of naturally derived castor oil, which has a high degree of functionality, making it an extremely useful excipient. However, this increased...
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Super Refined™ Oleic Acid
Highly purified oleic acid is used as a co-emulsifier in topical pharmaceutical formulations. Ideal for nasal drug delivery and as a penetration enhancer in transdermal formulations. In addition, it...
Croda offers a breadth of high purity ingredients that lend themselves well to solubilising a poorly water soluble drug, stabilising it once it’s in solution, and creating SEDDS and SMEDDS formulations. The list is constantly growing, and we strive to work with our customers to provide them with a solution they need!

Crodasol™ HS HP
Crodasol HS HP is a high purity nonionic surfactant which provides excellent solubilisation properties. Compliant to the PhEur monograph, it is a mixture of monoesters and diesters of...

Croduret™ 40
Crodurets are vegetable-derived nonionic surfactants that differ in their degrees of ethoxylation. Widely used in a variety of oral formulations, they are virtually tasteless solubilisers for vitamins...

Super Refined™ CCMG 400
Super Refined CCMG 400 is a multi-compendial, high purity mixture of caprylocaproyl polyoxylglycerides. It is ideal for use as a surfactant or co-solvent in self-emulsifying drug delivery systems...

Super Refined™ GMCC
Super Refined™ GMCC is a high purity mixture of monoglycerides and diglycerides of caprylic and capric acids. It is used to produce stable emulsions and to modify viscosity. It functions as a...
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Super Refined™ L18 POG
Super Refined™ L18 POG is a high purity mixture of mono-, di-, and triesters of glycerol, and mono- and diesters of polyethylene glycols, with the predominant fatty acid concentration stemming from...
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Super Refined™ O18 POG
Super Refined™ O18 POG is a high purity mixture of mono-, di-, and triesters of glycerol, and mono- and diesters of polyethylene glycols with the predominant fatty acid concentration stemming from...

Super Refined™ P35 Castor Oil
Super Refined P35 Castor Oil is a multi-compendial, high purity castor oil derivative, resulting from the reaction of glycerol ricinoleate and 35 mols of ethylene oxide. It is intended for use in...
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Super Refined™ PGML
Super Refined™ PGML is a high purity mixture of propylene glycol and esters of lauric (C12) acid. More specifically, as part of the Type II classification, it has at least a 90% concentration of...

Super Refined™ Polysorbate 20
Super Refining removes impurities, preventing adverse interactions with APIs and enhancing the stability of pharmaceutical formulations. Super Refined Polysorbates offer the complete solution when...

Super Refined™ Polysorbate 60
Super Refined Polysorbates solubilise and stabilise the most sensitive active ingredients across dosage forms including injectable and oral. Super Refining removes impurities (including primary and...

Super Refined™ Polysorbate 80
Super Refined Polysorbates solubilise and stabilise the most sensitive active ingredients across dosage forms including injectable and oral. Super Refining removes impurities (including primary and...
Croda offers a breadth of high purity ingredients that lend themselves well to solubilising a poorly water soluble drug, stabilising it once it’s in solution, and creating SEDDS and SMEDDS formulations. The list is constantly growing, and we strive to work with our customers to provide them with a solution they need!

Super Refined™ DEGEE
Super Refined DEGEE is a multi-compendial, high purity glycol ether. This clear, colourless liquid demonstrates outstanding permeation enhancement and improved delivery and bioavailability for topical...

Super Refined™ PEG 300
The Super Refined PEG range is a series of Super Refined polyethylene glycols, offering pharmaceutical formulators highly purified hydrophilic excipients that can enhance active and formulation...

Super Refined™ PEG 400
The Super Refined PEG range is a series of Super Refined polyethylene glycols, offering pharmaceutical formulators highly purified hydrophilic excipients that can enhance active and formulation...

Super Refined™ PEG 600
Super Refined PEGs are solvents for use with the most sensitive active ingredients across dosage forms including injectable and oral. Super Refining removes polar impurities (including primary and...

Super Refined™ Propylene Glycol
Super Refined Propylene Glycol is a highly purified propylene glycol that has a wide use in pharmaceutical formulations as a solvent, stablilising agent, water-miscible cosolvent, plasticiser,...

Super Refined™ DMI
High purity liquid for use with poorly soluble hydrophilic and hydrophobic actives. Enhances the formulation and API stability in transdermal delivery systems. Recommended topical usage levels of...
Croda offers a breadth of high purity ingredients that lend themselves well to solubilising a poorly water soluble drug, stabilising it once it’s in solution, and creating SEDDS and SMEDDS formulations. The list is constantly growing, and we strive to work with our customers to provide them with a solution they need!
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Span™ 20 HP
A high purity version of Span 20 tested against the USP/NF, PhEur and JPE monographs. This HP grade offers lower moisture levels as well as lower peroxide and acid values. Recommended use level is 0...
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Span™ 80 HP
A high purity version of Span 80 tested against both PhEur and USP monographs. This HP grade offers lower moisture levels as well as lower peroxide and acid values. Recommended topical usage levels of...
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Cithrol™ GMO HP
High purity oleic acid grade with a GMO content of 92% minimum. Offers controlled drug release and enhances active bioavailability. Membrane penetration enhancer. W/O emulsifier and O/W emulsion...