Bioactive Lavandula angustifolia essential oil-loaded nanoemulsion dressing for burn wound healing. In vitro and in vivo studies

The aim of this study was to develop a dressing with bioactive lavender in a new form of nanoemulsion, and to verify its biosafety and effectiveness in burn wound healing. As part of this research, the composition of the bioactive carrier of lavender oil in the form of a nanoemulsion obtained using ultrasound was optimised. The mean particle size of the internal phase and polydispersity were determined using the dynamic light scattering method using a Zestasizer NanoZS by Malvern and using cryo-transmission electron microscopy (TEM). These studies confirmed that the selected formulation had a particle size of approximately 180 nm and remained stable over time. The preparation was also subjected to rheological analysis (viscosity approximately 480 mPa·s) and a pH test (approximately 6). A macroemulsion (ME) with the same qualitative composition was developed as a reference. Nanoformulations and MEs were tested for skin penetration using Raman spectroscopy in an in vitro model. Research has shown that both formulations deliver oil to living layers of the skin. Subsequently, studies were conducted to confirm the effect of lavender oil in emulsion systems on the mitigation of the inflammatory reaction and its pro-regenerative effect on the wound healing process in an in vitro cell culture model. The safe concentration of the oil in the emulsion preparation was also determined based on preliminary in vivo tests of skin sensitisation and irritation as well as an hemocompatibility test of the preparation.

The Release of Perillyl Alcohol from the Different Kind of Vehicles

BACKGROUND

Skin cancers are the most common malignancy in humans, and the number of cases has increased dramatically in the past few decades. Therefore, it is very important to carry out studies concerning new and safer anticancer natural agents (e.g. perillyl alcohol) and modern drug delivery systems, such as nanoformulations, which increase their bioavailability.

OBJECTIVES

The aim of this work was to obtain different kinds of topical vehicles formulation and compare their efficiency in the release of perillyl alcohol. The release kinetics was determined by using certain selected mathematical models.

METHOD

Formulations of a hydrogel, O/W nanoemulsion, O/W macroemulsion and nanostructured lipid carrier were developed as carriers for perillyl alcohol - one of the promising anticancer natural agents. The release study of the active agents was carried out using the Spectra/Por Standard Regenerated Cellulose membrane, at temperature T=320C. The concentration of active agents in the receptor solution was analyzed by high performance liquid chromatography. The release kinetics was determined by using selected mathematical models.

RESULTS

The results of our release studies have shown that the highest and comparable amount of perillyl alcohol was released from hydrogel (35.72 ± 0.21%), NLC (35.54 ± 1.48%) and nanoemulsion (34.87 ± 4.49%). The release was found to follow Fickian diffusion in the case of hydrogel and macroemulsion, while an anomalous mechanism was observed in the case of nanoformulations. Nevertheless, the obtained nanoformulations, as well as a conventional hydrogel, may be considered potential vehicles in topical delivery of perillyl alcohol.