Investigation of Effects of Terpene Skin Penetration Enhancers on Stability and Biological Activity of Lysozyme

Abstract

The transport of proteins through skin can be facilitated potentially by using terpenes as chemical enhancers. However, we do not know about the effects of these enhancers on the stability and biological activity of proteins which is crucial for the development of safe and efficient formulations. Therefore, this project investigated the effects of terpene-based skin penetration enhancers which are reported as nontoxic to the skin (e.g., limonene, p-cymene, geraniol, farnesol, eugenol, menthol, terpineol, carveol, carvone, fenchone, and verbenone), on the conformational stability and biological activity of a model protein lysozyme. Terpene (5% v/v) was added to lysozyme solution and kept for 24 h (the time normally a transdermal patch remains) for investigating conformational stability profiles and biological activity. Fourier transform infrared spectrophotometer was used to analyze different secondary structures, e.g., α-helix, β-sheet, β-turn, and random coil. Conformational changes were also monitored by differential scanning calorimeter by determining midpoint transition temperature (Tm) and calorimetric enthalpy (ΔH). Biological activity of lysozyme was determined by measuring decrease in A (450) when it was added to a suspension of Micrococcus lysodeikticus. The results of this study indicate that terpenes 9, 10, and 11 (carvone, L-fenchone, and L-verbenone) decreased conformational stability and biological activity of lysozyme significantly (p < 0.05) less than other terpenes used in this study. It is concluded that smaller terpenes containing ketones with low lipophilicity (log K (ow) ∼2.00) would be optimal for preserving conformational stability and biological activity of lysozyme in a transdermal formulation containing terpene as permeation enhancer.

Transdermal Drug Delivery System of Aceclofenac for Rheumatoid Arthritis and the Effect of Permeation Enhancers: In vitro and in vivo Characterization

“…The terpene based enhancers are reported to be nontoxic to the skin. These enhancers do not affect the stability and biological activity of the drugs like proteins and peptides even (Varman and Singh, 2012). The present study showed the dominant permeation enhancement of limonene over the nonionic surfactant Span 20.…”

Essential oil components and cytochrome P450 enzymes: a review

“…Another therapeutic use of EO components are transdermal drug delivery systems. Nowadays one of the favoured routes for therapeutically effective drugs is the transdermal route, because of several advantages such as bypassing the first‐pass effect, better patient compliance, and the sustained release of drugs over a period of time . There are many studies investigating the permeation‐enhancing effect of EO components, particularly of monoterpenes and phenylpropanoids on the permeation behaviour of different skin‐delivered pharmaceuticals .…”

“…Moderately polar components have a higher permeation rate than lipophilic compounds . The EO components carveol, carvone, eugenol, fenchone, geraniol, limonene, linalool, methyleugenol, and verbenone are commonly used in massage oils, cutaneous topical products, and permeation enhancers, and have the potential to permeate the skin and have pharmacological effects . These EO components and their influence on CYP enzymes are described below.…”

“…Nowadays one of the favoured routes for therapeutically effective drugs is the transdermal route, because of several advantages such as bypassing the first-pass effect, better patient compliance, and the sustained release of drugs over a period of time. 36 There are many studies investigating the permeationenhancing effect of EO components, particularly of monoterpenes and phenylpropanoids on the permeation behaviour of different skin-delivered pharmaceuticals. 37 A great barrier for transdermal drug delivery is the stratum corneum, which is the outermost layer of the skin, and therefore natural or synthetic penetration enhancers are commonly used in pharmaceutical formulations.…”

Terpene-Containing PEGylated Liposomes as Transdermal Carriers of a Hydrophilic Compound

“…This difference may be due to swelling of the stratum corneum upon hydration, which reduces the effective solubility of nonpolar drugs in the membrane. 32) Drug release from vesicles in the stratum corneum is an important step affecting transdermal flux. The rate and amount of released drug is a balance between two factors: 1) drug affinity for vesicles and 2) drug solubility in lipids of the stratum corneum.…”