How do penetration enhancers work?
The skin is an excellent barrier, and that can make it challenging for topical drug delivery. Penetration enhancers generally function by one of two mechanisms, either by enhancing the solubility of the drug in the skin or by increasing intercellular lipid fluidity, allowing an easier pathway through the skin.
Our Super Refined™ Arlasolve™ DMI works by increasing the solubility of APIs in the skin. The figure shows how the addition of 10% Arlasolve DMI to a formulation containing a model hydrophilic API results in an 18% increase in API delivered through the stratum corneum, and into the epidermis.
Super Refined Oleic Acid is a high purity lipid that can act as a penetration enhancer. It improves drug delivery into the skin by temporarily and reversibly disrupting the ordered intercellular lipids. When the intercellular lipids are less ordered and have greater fluidity, it can be easier for APIs to pass between them, resulting in greater topical delivery.
Our Super Refined penetration enhancers can improve the delivery of APIs into and through the skin, and our formulation expertise can help to guide you in the right direction on which penetration enhancer to choose. As Super Refined excipients, they also bring with them the benefits of improved API stability, lower colour and fewer oxidative degradation products.
Super Refined™ pharmaceutical excipients

.jpg&mn=healthcare&w=768&xr=0&yr=0&xfp=6&yfp=6&hash=024E1E255E3A56F566F39BD6B73AD51719C138999FEC74AA)
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...
Utilising HLB method for topical formulations

View our range of penetration enhancers
Our range of Super Refined™ penetration enhancers can be used in topical formulations including creams, ointments, gels and transdermal patches.

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...

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™ Lauryl Lactate
Super Refined Lauryl Lactate is a highly purified emollient and penetration enhancer, usually used in topical formulations.

Super Refined™ Oleyl Alcohol
Highly purified lipid-based solubiliser and skin penetration enhancer. Ideal for wetting and dispersing actives within topical creams and ointment applications. It is an ideal excipient for use in...
.jpg&mn=healthcare&w=768&xr=0&yr=0&xfp=6&yfp=6&hash=024E1E255E3A56F566F39BD6B73AD51719C138999FEC74AA)
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...

Super Refined™ IPM
Highly purified version of Crodamol IPM. Solvent used in topical formulations. Rapid absorption into the skin. Recommended topical usage levels of 0.5-5%.

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,...
.jpg&mn=healthcare&w=768&xr=0&yr=0&xfp=6&yfp=6&hash=B7A014F4ED7B52AFF22F83F2BEDE8A5919C138999FEC74AA)
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...
Product finder
View our range of penetration enhancersSEDDS and SMEDDS
SEDDS and SMEDDS drug delivery systems 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.
Learn morePharmaceutical solvents
Achieving API solubility is one of the big challenges faced by formulators, with many APIs having low solubility. Our range of Super Refined pharmaceutical solvents can address this challenge, providing a range of polar and non-polar solvents that not only provide solubility, but also excellent stability for APIs.
Learn morePharmaceutical solubility guide
As API solubility continues to present challenges for the pharmaceutical formulator, Croda has determined the solubility of a range of actives in a number of Croda’s high purity excipients.
Learn more