Piper aduncum Essential Oil Rich in Dillapiole: Development of Hydrogel-Thickened Nanoemulsion and Nanostructured Lipid Carrier Intended for Skin Delivery

Abstract

The essential oil extracted from the leaves of Piper aduncum, an aromatic plant from the Amazon region, is rich in dillapiole and presents anti-inflammatory activity. In this study, nanoemulsions (NE) and nanostructured lipid carriers (NLC), which are biocompatible nanostructured systems of a lipid nature, were prepared by high-pressure homogenization for the yet unexplored skin delivery of dillapiole. The addition of hydroxyethylcellulose produced hydrogel-thickened NE or NLC in view to improving the viscosity and skin adherence of the nanoformulations. Formulations were characterized with respect to dillapiole content, droplet size, polydispersity index, zeta potential, morphology, rheological behavior, bioadhesion, skin permeation profile, and in vitro irritancy (HET-CAM). The formulations developed presented spherical, homogeneous nanometric particle size (around 130 nm), narrow polydispersity index (<0.3), and negative zeta potential (around −40 mV). Dillapiole content was slightly lower in NLC compared to NE since the production process involves heating. The hydrogels containing nanocarriers showed pseudoplastic behavior with bioadhesive characteristics. The developed formulations exhibited a controlled release profile, dillapiole delivery up to the dermis, the layer of interest for anti-inflammatory potential, and low irritant potential in the chorioallantoic membrane (HET-CAM). Both hydrogels-thickened NE and NLC seemed to be promising formulations for skin delivery of Piper aduncum essential oil.

Composition and Biological Activity of the Essential Oils from Wild Horsemint, Yarrow, and Yampah from Subalpine Meadows in Southwestern Montana: Immunomodulatory Activity of Dillapiole

“…One of the issues noted for this research is that DMSO was required for solubilizing our samples, which may be problematic in the development of new therapeutics. However, recent studies by Carneiro et al [ 52 ] indicate that nanoemulsions and nanostructured lipid carriers could be used for the delivery of essential oils and dillapiole. Thus, nanocarriers loaded with dillapiole could potentially represent an interesting strategy for developing this compound for the treatment of inflammation.…”

Progress of nanopreparation technology applied to volatile oil drug delivery systems

“…Since SLN suffers from drug efflux defects and low hydrophilic drug loading capacity during storage, NLC is further designed to address these drawbacks, resulting in an ideal loading capacity and greater drug accumulation capacity of NLC, where the drug is essentially undischarged during storage. Many herbal volatile oils or major components have been co-incorporated into NLC to enhance therapeutic efficacy, including pepper oil [ 98 ], fennel oil [ 99 ], cinnamon oil [ 100 ], thyme oil [ 101 ], clove oil [ 102 ], cardamom oil [ 103 ], peppermint oil [ 104 ], and others. Notably, the drug-carrying capacity of NLC is higher than that of LS and SLN because NLC is able to contain three different volatile oils (lavender, peppermint, and rosemary) at the same time and achieve enhanced therapeutic effects for the treatment of neurodegenerative diseases [ 105 ].…”

“… Industrial production is difficult, and research on NLC is not very thorough. Pepper [ 98 ], Fennel [ 99 ], Cinnamon [ 100 ], Thyme [ 101 ], Clove [ 102 ], Cardamom [ 103 ], Peppermint oil [ 104 ] Self-emulsifying drug delivery system (SEDDS) Does not involve any heating or solvent evaporation steps to improve oral bioavailability. There is still little research in this direction.…”

“…Pepper [ 98 ], Fennel [ 99 ], Cinnamon [ 100 ], Thyme [ 101 ], Clove [ 102 ], Cardamom [ 103 ], Peppermint oil [ 104 ]…”

Biomedical Approach of Nanotechnology and Biological Risks: A Mini-Review

“…In vitro cytotoxicity studies were also carried out in Caco-2 cells, demonstrating the nanosystem's non-cytotoxic profile. The essential oil of Piper aduncum, an aromatic plant from the Amazon region with inherent anti-inflammatory activity, was encapsulated by Carneiro et al (2022) [180] in nanostructured lipid carriers through the high-pressure homogenization technique to develop a cutaneous administration of its bioactive compounds. In the end, the particles obtained a size of around 130 nm, bioadhesive characteristics, and a controlled release profile with low irritant potential on the chorioallantoic membrane.…”