New findings on the incorporation of essential oil components into liposomes composed of lipoid S100 and cholesterol

Abstract

The encapsulation of essential oil components into liposomes was demonstrated to improve their solubility and chemical stability. The aim of the present study is to investigate the effect of chemical structure, henry constant (H " ) value and aqueous solubility of essential oil components on their liposomal encapsulation. Based on ethanol injection method, the essential oil components (estragole, eucalyptol, isoeugenol, pulegone, terpineol, and thymol) were encapsulated in lipoid S100-liposomes. Static headspace gas chromatography method showed that H # of estragole, isoeugenol and eucalyptol was approximately 10 times greater than that of pulegone, terpineol and thymol. Besides, dynamic light scattering and diffraction technique revealed that all liposomal vesicles were of micrometric in size and the presence of phenols, isoeugenol and thymol, promoted enlargement of vesicles. Incorporation in liposomes was better (encapsulation efficiency > 90 %) for the essential oil components exhibiting low aqueous solubility, estragole, isoeugenol, and pulegone. Besides, efficient entrapment in liposomes (loading rate > 18 %) was obtained for isoeugenol, terpineol and thymol. This suggests that the presence of hydroxyl group in the structure and exhibiting lower H " ameliorated the entrapment of essential oil components into liposomes. Furthermore, release rate from liposomes varied among the investigated essential oil components and it was controlled by loading rate of essential oil components into liposomes, size of liposomal batches, location of essential oil components within lipid bilayer, and cholesterol incorporation rate of liposomes. Finally, liposomal encapsulation of isoeugenol, pulegone, terpineol, and thymol was suitable to protect them as a considerable concentration was retained in liposomes after 10 months with respect to initial concentration.

Comparison between Citral and Pompia Essential Oil Loaded in Phospholipid Vesicles for the Treatment of Skin and Mucosal Infections

“…Recently, they have been successfully proposed for the skin delivery of phytochemicals due to their high loading and carrier capabilities, as well as affinity with the skin [40]. The ability to potentiate the efficacy of essential oils was also demonstrated [41]. In previous studies, the optimal skin delivery performance of the phospholipid vesicles in the delivery of Santolina insularis essential oil were demonstrated [23].…”

Retention of Eucalyptol, a Natural Volatile Insecticide, in Delivery Systems Based on Hydroxypropyl‐β‐Cyclodextrin and Liposomes

“…The Henry's law constant was increased to 0.05, 0.07, 0.008, 0.009, 0.003, and 0.009 for Euc, estargole, isoeugenol, pulegone, terpineol, and thymol, respectively upon increasing the temperature from 30 to 60 °C. [ 25 ] The chromatogram obtained for eucalyptol at 60 °C did not show any additional peak or presence of a degradation product during the time of the analysis (8 min). The volatilization of Euc during the preparation of liposomes at 55 °C can explain the dramatic loss of this volatile agent.…”

“…HP‐β‐CD and essential oil components are able to affect the size of liposomes composed of unsaturated phospholipids. [ 25 ] Besides, polydispersity index values for all batches were less than 0.2, suggesting that liposomes suspensions were homogenous (Table 2). The zeta potential values for the various formulations were negative ranging between (−2 to −9 mV) suggesting that the presence of HP‐β‐CD or Euc did not affect the zeta potential values.…”

“…However, Hammoud et al. [ 25 ] studied the encapsulation of Euc in liposomes composed of unsaturated soybean phospholipid (Lipoid S100) and the results showed that CL loading Euc had a low loading capacity value of Euc (1.1 µg of drug mg −1 of total organic components). The encapsulation of Euc in DCL system was 38 times greater than CL formulations with LC values of 0.6 µg of Euc mg −1 of powder (Table 6).…”

‐sitosterol and gentisic acid loaded 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine liposomal particles

“…Liposomes represent spherical micrometric or nanometric particles comprising a central aqueous compartment, encircled by one or more bilayers which are composed mainly of phospholipids and sterols. Biocompatible and biodegradable liposomal particles are suitable for delivery of various bioactive components, including vitamins, polyphenols, carotenoids, peptides, enzymes, essential oils (Hammoud, Gharib, Fourmentin, Elaissari, & Greige-Gerges 2019;Jovanović et al 2018;Reidel, Camussone, Archilla, Calvinho, & Veaute 2019). During the encapsu-lation of active principles in liposomal vesicles, lipophilic compounds can be located within the lipid bilayer, hydrophilic substances in the aqueous internal cavity, whereas amphiphilic components are found at the waterlipids interface (Hammoud et al 2019).…”