Systematic Review on the Effectiveness of Essential and Carrier Oils as Skin Penetration Enhancers in Pharmaceutical Formulations

Abstract

Oils, including essential oils and their constituents, are widely reported to have penetration enhancement activity and have been incorporated into a wide range of pharmaceutical formulations. This study sought to determine if there is an evidence base for the selection of appropriate oils for particular applications and compare their effectiveness across different formulation types. A systematic review of the data sources, consisting of Google Scholar, EMBASE, PubMed, Medline, and Scopus, was carried out and, following screening and quality assessment, 112 articles were included within the analysis. The research was classified according to the active pharmaceutical ingredient, dosage form, in vitro/in vivo study, carrier material(s), penetration enhancers as essential oils, and other chemical enhancers. The review identified four groups of oils used in the formulation of skin preparations; in order of popularity, these are terpene-type essential oils (63%), fatty acid-containing essential oils (29%) and, finally, 8% of essential oils comprising Vitamin E derivatives and miscellaneous essential oils. It was concluded that terpene essential oils may have benefits over the fatty acid-containing oils, and their incorporation into advanced pharmaceutical formulations such as nanoemulsions, microemulsions, vesicular systems, and transdermal patches makes them an attractive proposition to enhance drug permeation through the skin.

WITHDRAWN: Novel hydro-alcoholic sanitizer model with minimum alcohol content and fortified with eugenol and cinnamaldehyde as natural antimicrobial boosters

“…In addition, eugenol and cinnamaldehyde are already used in some topical application in dermatological drugs to treat fungal infections [48]. The essential oils that bear large quantities (> 80%) of eugenol and cinnamaldehyde are also used as skin penetration enhancers to facilitate transdermal delivery of drugs [49]. Interestingly, despite its skin irritation properties, eugenol showed promising activity in treatment of dermatitis especially after formulation in polymeric nanocarriers [50].…”

Development of Nanoemulsions for Topical Application of Mupirocin

“…Terpene essential oils have been widely reported as efficacious in the enhancement of transdermal drug permeation following incorporation into advanced pharmaceutical formulations such as nanoemulsions [ 19 ]. They disturb the stratum corneum lipid reversibly to enhance drug permeation and diffusivity through the skin [ 20 ].…”

Essential Oils Distilled from Colombian Aromatic Plants and Their Constituents as Penetration Enhancers for Transdermal Drug Delivery

“…They have been included in different types of topical formulations, free or encapsulated, in diverse nano TDD systems, such as some of those that were previously named [ 7 ]. Terpene-rich EOs such as eucalyptus oil (1,8-cineole), clove oil (eugenol), peppermint oil (menthol and menthone), limonene, turpentine oil (α-pinene and β-pinene), and menthol have been identified as the most frequently used compounds for PEs [ 8 ], however, others such as thyme, basil, angelica, and fennel EOs have also demonstrated interesting PE activities [ 5 , 9 ]. One of the most common methodologies for studying TDD in vitro or ex vivo is the diffusion cell system (Franz cells) [ 10 ].…”